Siemens TIWAY 1 User Manual

SIMA

TIC TIWAY 1

UNILINK Host Adapter

User

Manual

Order Number: PPX:TIWAY–8121–2
Manual Assembly Number: 2587871–0045
Second Edition

CHAPTER 1

THE

UNILINK HOST ADAPTER

1.1 INTRODUCTION

The

UNILINK Host Adapter
interface
devices
the “adapter” in this manual, is a hardware and software extension of the
original

product that allows a host computer to operate and control secondary

on a TIWAY I network. The UNILINK Host Adapter

TIWAY I Host Adapter

, Figure

.

1–1 is a second generation host computer

, also referred to as

Figure 1–1 UNILINK Host Adapter

UNILINK HOST

USER MANUAL

ADAPTER1–1

THE UNILINK HOST ADAPTER

1.2 FEATURES

The

hardware is composed of the UNILINK Adapter, shown in Figure 1–1, with
a

plug-in Personality Interface Module (PIM) PPX:500–6224.
in Figure 1–2, contains the software that causes the UNILINK Adapter to
operate

as the UNILINK Host Adapter

.

Figure 1–2 Personality Interface Module (PIM)

The PIM, shown

Figure 1–3 illustrates the basic structure of the UNILINK Host Adapter. The
corresponding physical features are shown in Figure 1–4. It includes an
RS–232–C/RS–423–A compatible host port that supports the Non-Intelligent
Terminal Protocol (NITP) used by the original TIWAY I Host Adapter, or the
BDLC

protocol, an advanced, byte-oriented subset of the HDLC protocol. Also,

there are two TIWAY I interface ports and an external I/O point block.

UNILINK HOST

USER MANUAL

ADAPTER 1–2

THE UNILINK HOST ADAPTER

Host

Computer

RS–232–C/RS–423A

Interface

Host

(Command Processor)

TIWA

Y I

Interface

TIWA

Y I

Input Point

External

Output Point

Network

Secondaries

Figure 1–3 UNILINK Host Adapter Block Diagram

UniLink
Host Adapter

Host

PPX:500–711

Computer Port

TIWA

Port

1

Y I Ports

Port

2

Port

1, Dual Local Line media ports shown here.

3

Power Connections

Port

4

External I/O Points

Figure 1–4 UNILINK Host Adapter Physical Features

AC

GND

NEUTACLINE

1

2 3 4 5

I/O

UNILINK HOST

USER MANUAL

ADAPTER1–3

THE UNILINK HOST ADAPTER

The

features of the UNILINK Host Adapter include:



The adapter is noise hardened for factory floor use.

 There are internal diagnostics tests to check the internal operation

when

powered-up or reset, and during normal operation. There is also a

selectable

 The adapter can be reset locally with an internal switch or remotely

with

test mode that is set locally

a host issued command.

.

 The

 The adapter is backward compatible with TIWAY I Host Adapter

 The adapter includes an independent host communications port

 This



 The

 The

 The

adapter supports secondary-to-secondary communications without

complex

software

capable of serial communications at 38.4K baud. This port operates
simultaneously

throughput and data integrity. This protocol also allows up to 32
UNILINK Host Adapters to be multidropped (via a modem) from the
same

The adapter supports or provides the following TIWAY I features.

fault

devices

computer
another request when using the advanced host communication
protocol.

host software or additional hardware.

and drivers.

with the network ports.

host port provides an optional advanced host protocol for improved

host computer RS–232–C/RS–423–A port.

adapter supports the TIWAY I redundant media feature, providing

tolerant communications in case of a media failure.

adapter supports communication with multiple network secondary

concurrently for higher network throughput.

adapter supports concurrent network request processing. The host

does not have to wait

for a request to complete before issuing

UNILINK HOST

USER MANUAL

 Commands are provided for background data collection. The adapter

can be configured to collect data for the host computer by storing the
most current data values in internal memory. Another command then
retrieves

ADAPTER 1–4

the data.

THE UNILINK HOST ADAPTER

 The adapter is configurable for a variety of applications needs and

includes multiple host computer support, allowing several host
computers to communicate with the secondary devices on the same
T I WAY

 The adapter provides transaction statistics collection to aid network

performance

1.3 TYPICAL NETWORK APPLICATIONS

I network.

tuning.

Figure

1–5 illustrates

a typical single host network managing a process control
application. The host computer application directs the secondary devices
through

the UNILINK Host Adapter and the TIWAY I network. Commands are
provided for downloading or uploading data from the host computer to the
secondary

devices and for checking the status of an individual device.

Host

Computer

RS–232–C/RS–423–A
Host Interface Cable

UNILINK

TIWAY

I

UniLink Host Adapter ( MHU)

Figure 1–5 Single Host Network

UNILINK HOST

USER MANUAL

ADAPTER1–5

THE UNILINK HOST ADAPTER

The

flexibility of the UNILINK Host Adapter also provides for
illustrated in Figure 1–6. In addition to the process control application, your
main plant system can link to the same network to track work-in-progress,
adjust

schedule loads for peak efficiency, and collect product cost data. W
additional UNILINK Host Adapter, you can also add a personal computer
workstation

to the network for statistical quality control or other uses.

multiple hosts as

ith an

Host

Computer

UniLink

Adapter (MHU)

Host

Computer

UNILINK

UniLink Host

Adapter (MHU)

Figure 1–6 Multiple Host Network

Host

UNILINK

UNILINK HOST

USER MANUAL

ADAPTER 1–6

THE UNILINK HOST ADAPTER

1.4 TIWA

Y I SYSTEM CHARACTERISTICS

TIWAY I is a bus structure Local Area Network (LAN) designed for industrial
environments. The TIWAY I network connects a series of Texas Instruments
Programmable Controllers (P/Cs) and other devices to one or more host
computers. W
any

of the following Siemens products:

 SIMATICTI520/SIMATICTI530/

 SIMATICTI560/SIMATICTI565 P/Cs





 IT–111, IT–121, IT–121A, IT150, and IT–160 Intelligent Tank

The P/Cs are connected to a TIWAY I network through Network Interface
Modules (NIMs). The PM550 P/C can also be connected with a Computer
Interface Module (CIM), but
Secondary
as

the following, to be connected to a TIWAY I network.

ith the network, you can obtain, modify or replace data stored in

SIMATICTI520C/SIMATICTI530C P/Cs

PM550/PM550C P/Cs
5TI, Series 102, 103 P/Cs

Transmitters

Adapter is a

(ITT

s)

it limits the configuration choices. The UNILINK

TIWAY I interface device that allows other devices, such

 Robots



Computer numerical controlled machines

 Non-SIMA



Intelligent instruments



Computer equipment

TIWAY I gateways are also available for connecting the Fisher, Foxboro, and
Honeywell networks to TIWAY I. However, you cannot use a gateway and a
UNILINK
satisfy today’s factory requirements for acquiring data and controlling
manufacturing
network that uses an advanced data link protocol.

Series 500 controllers can be connected with PEERLINK for high speed
transfer of small amounts of data between controllers. The PEERLINK is a
solution for applications where one or more Series 500 controllers are
dependent

Host Adapter in the same TIWAY I network. TIWAY I

on high speed transfer of data from another Series 500 controller

TIC programmable controllers

processes.

It is a noise-hardened serial binary communications

is designed to

.

UNILINK HOST

USER MANUAL

ADAPTER1–7

THE UNILINK HOST ADAPTER

With

appropriate host software, an operator can program, monitor
any P/C or other intelligent device on the TIWAY I network from a single
location.

The importance of the UNILINK Host Adapter is that it provides a
communication link between the TIWAY I network and one or more host
computers. Figure 1–7 is a diagram representing the various host computers
that

can be connected to a UNILINK Host Adapter

can

be controlled in a TIWAY I network.

IBM

DEC

Y

ICC 6000

CVU



5000

TIPC

DEC

PDP–
11

/

X

S
E
R
T
E
S
1

, and the typical devices that

Other

M

IBM



PC/

XT/

AT

I

PC/

H

XT/
I

S

/

M

I
C
R

AT

O
S

, and control

NIM

5TI

UniLink

Host

Adapter

Honeywell

Fisher

Gateways

Y I

TIWA

Secondary

Adapter

NIM

SIMATIC

TI520

PEERLINK

NIM

PM550

NIM

SIMATIC

TI560

PEERLINK PEERLINK PEERLINK

NIM

SIMATIC

TI565

NIM

SIMATIC

TI530/

TI530C

NIM

Int.
Tank
Xmtr.

Robots

CNC

Int. Scales

Figure 1–7 TIWAY I Network

You cannot use a UNILINK Host Adapter in a TIWAY I network that also
contains
Host Adapter. Chapter 4 provides information on interfacing the adapter to a
TIWAY

a TIWAY I Gateway or Network Control Module (NCM) or a TIWAY I

I network.

Map

Foxboro

Other

Int. Devices

Others

UNILINK HOST

USER MANUAL

ADAPTER 1–8

THE UNILINK HOST ADAPTER

1.5 INSTALLATION

Instructions for installing the UNILINK Adapter and the UNILINK Host
Adapter PIM are given in the UNILINK Adapter Installation and Operation
Manual (PPX:TIWAY–8106). It provides the electrical and mechanical
installation

Chapter 2 discusses the different operational modes and how they are
configured.

instructions and guidelines for the the UNILINK Host Adapter

.

Chapter
dipswitches

Chapter
your

1.6 TECHNICAL

If you need assistance with the installation an operation of this equipment,
contact
you
States,

1.7 CUSTOMER

If you need assistance in placing an order, returning a product, or learning
about product availability, contact your Siemens Industrial Automation, Inc.
distributor
or

3 discusses the host computer interface port, Port 3, and how to set the

to establish communications.

4 discusses the TIWAY I interface ports, Ports 1 and 2, and how setup

network.

ASSIST

your Siemens Industrial Automation, Inc. distributor or sales agent. If

need assistance in contacting your distributor or sales office in the United

call 800–964–41

SER

or sales agent. If you need

sales office in the United States, call 800–964–41

ANCE

14.

VICE CENTER

assistance in contacting your distributor

14.

UNILINK HOST

USER MANUAL

ADAPTER1–9

CHAPTER

2

OPERA

TION AND APPLICA

2.1 INTRODUCTION

This

chapter provides an introduction to the UNILINK Host Adapter operation
and how it can be used in typical applications. Y
the

complete command syntax and to the Glossary for help with any unfamiliar
terms. Network planning forms are located in Appendix E, Appendix F, and
Appendix

G.

ou should refer to Chapter 5 for

2.2 COMMAND PROCESSING

The

UNILINK Host Adapter commands are a set of functional tools to help you
direct network applications. Each command consists of a one-byte command
code and one or more parameters as shown in Figure 2–1. Most parameters
have

default values that
network
you can improve
network needs. Figure 2–2 illustrates the relative performance and flexibility
gained

and expand it with minimal software changes. As your network grows,

network efficiency by redefining the parameters to match your

with using additional commands.

were selected to help you quickly install an operational

TION

Command

Code

Parameter#1Parameter

#2

Figure 2–1 Command String Structure

Parameter

#n

UNILINK HOST

USER MANUAL

ADAPTER2–1

OPERATION

AND

APPLICATION

Network
Manager
Commands

Performance
and
Applications
Flexibility

Mode Independent
Commands

Basic HIU
Commands

Extended HIU
Commands

Configure Adapter
Commands

   

NUMBER OF COMMANDS

Figure 2–2 Performance vs Commands

Communications between the host computer and the UNILINK Host Adapter
are

a series of commands and responses as illustrated in Figure 2–3. For every
command sent, there will be a response. The response will be one of the
following.

UNILINK HOST

USER MANUAL

 An





ADAPTER 2–2

acknowledgment that the command was received
A command response
The ERROR RESPONSE

OPERATION

AND

APPLICATION

Secondary

Secondary

Host
Computer

Commands

UNILINK
Host Adapter

Responses

Figure 2–3 Host Computer To UNILINK Host Adapter

Communications

Commands are checked for errors before they are executed. The ERROR
RESPONSE is a special response that returns a code indicating the type of
error. If an error is found, the command will not be executed and the ERROR
RESPONSE
network request does not complete within the host command timeout. The
possible error codes that may be returned in the ERROR RESPONSE and
corrective

will

be returned. The ERROR RESPONSE will also be returned if a

actions to take are listed in Chapter 6.

UNILINK HOST

USER MANUAL

ADAPTER2–3

OPERATION

AND

APPLICATION

2.3 FUNCTIONAL ORGANIZATION AND OPERATING MODES

The

UNILINK Host Adapter is organized into two primary functions; the Host
Interface Unit (HIU) function and the Network Manager (NM) function. An
adapter
form
of

In addition to the above modes, there are two Emulate Host Adapter (EHA)
modes

can be configured with one

a Master Host Interface Unit (MHIU). The MHIU, HIU, and NM are three

the six configurable operating modes.

and a Standalone Network Manager (SANM) mode.

of these functions or they can be combined to

2.3.1

Host Inter

The primary purpose of the Host Interface Unit (HIU) function is to establish
communications between the host computer and the secondary devices on a
TIWAY I network. The HIU uses the memory in the adapter for macro buffers
and
are

used to store
connecting,
delays

Commands
the host requests are processed and queued to the Network Manager function
for

routing to the appropriate secondary device. The Master Host Interface Unit

(MHIU)

face Unit Function

to store host-to-secondary statistics as shown in Figure

macro commands and responses. Macros provide a method for

disconnecting, or sending a Primitive

in host processing. Macros are discussed further in Paragraph 2.10.1.

are received from the host computer and checked for validity

mode combines the HIU function and the Network Manager function.

to a secondary device without

2–4. Macro buffers

. Then

UNILINK HOST

USER MANUAL

ADAPTER 2–4

OPERATION

AND

APPLICATION

HIU

Establishes communications
between the host computer
and the secondary devices.

Uses memory for:

Macro Buffers

(Dynamically allocated)

Host–to–Secondary Statistics

Figure 2–4 Host Interface Unit Function

Part

of the statistics

issued

to

connect and disconnect secondaries, the specified secondary address is

added

or deleted from the Secondary Log and a network request is queued into

the

Network Manager

memory area is used for a Secondary Log. As commands are

.

In the background, the adapter is continuously collecting statistics on the
number of commands processed, transactions completed on the network, and
other items. Commands to retrieve these statistics do not require network
transactions,

The following operating modes include the HIU function.









but return the information from the appropriate statistical area.

Master Host Interface Unit (MHIU)
Host Interface Unit (HIU)
Master Host Interface Unit/Emulate Host Adapter (MHIU/EHA)
Host Interface Unit/Emulate Host Adapter (HIU/EHA)

UNILINK HOST

USER MANUAL

ADAPTER2–5

OPERATION

AND

APPLICATION

2.3.2

Network Manager Function

Acting as the network primary, the Network Manager function is responsible
for

controlling the message traffic on the TIWAY I network as shown in Figure

2–5.

It

receives the requests from HIUs and stores them in a NM buffer

them

to the designated secondary devices, and returns the secondary response

to the HIU that issued the request. There can be only one adapter configured

the Network Manager function in any particular TIWAY I network.

with

This

function will only process Network Manager commands. These
control
and handle the background monitor and redundant media switching
operations. All network requests and responses are queued in the Network
Manager

the TIWAY I network operations, return network statistical information

buffers area.

, routes

commands

NM

Manages the message traffic on
the TIWAY I network.

Uses memory for:

Network Buffers
Network Stations

Figure 2–5 Network Manager Function

UNILINK HOST

USER MANUAL

ADAPTER 2–6

OPERATION

The following operational modes include the NM function. However, the
MHIU/EHA









mode does not provide access to the NM command set.

Master Host Interface Unit (MHIU)
Network Manager (NM)
Standalone Network Manager (SANM)
Master Host Interface Unit/Emulate Host Adapter (MHIU/EHA)

AND

APPLICATION

2.3.3

The Master Host Inter

The Master Host Interface Unit (MHIU) is a combination of the HIU and NM
functions
communicate with secondary devices through the HIU function and control
network
a

TIWAY I network may have the NM function.

as shown in Figure 2–6. A host computer connected to an MHIU

performance

face Unit Mode

through the NM function. Remember

can

, only one adapter in

HIU NM

MHIU

Figure 2–6 Master Host Interface Unit Diagram

UNILINK HOST

ADAPTER2–7

USER MANUAL

OPERATION

AND

APPLICATION

2.3.4 Typical

Both single and multiple host networks are supported by the UNILINK Host
Adapter. Figure 2–7 illustrates a typical single host network which uses an
MHIU

Network Applications

as the host interface and network manager

Host
Com­puter

UNILINK

UniLink Host Adapter ( MHU)

RS–232–C/RS–4
23–A
Host

Interface

Cable

TIWAY

.

I

Figure 2–7 Typical Single Host Network

Multiple
operating modes as illustrated in Figure 2–8 and Figure 2–9. Since the NM
function
and HIUs can use the total memory resources of the adapters for their
respective needs. This could be an advantage in large networks where the
additional

host

networks can be configured with a variety of adapters in different

is not in the same adapter with the HIU function in Figure 2–9, the NM

memory for NM buffers will increase network performance.

UNILINK HOST

USER MANUAL

ADAPTER 2–8

OPERATION

AND

APPLICATION

Host
Com­puter

UniLink Host
Adapter (MHU)

Figure 2–8 Typical Multiple Host Network

UNILINK

Host
Com­puter

UNILINK

UniLink Host
Adapter (MHU)

Host

Com-

puter

Host
Com­puter

UNILINK

(HIU)

UNILINK

Figure 2–9 NM Network

Host
Com­puter

UNILINK

(HIU)

UNILINK HOST

USER MANUAL

ADAPTER2–9

OPERATION

AND

APPLICATION

2.3.5 The

There are two modes available that provide an emulation of the TIWAY I Host
Adapter; the MHIU/EHA and the HIU/EHA. These modes are limited to the
base command codes 01 through 08, 20, 21, and FC through FF. The POLL
command,
will operate with applications software written for the TIWAY I Host Adapter.
The MHIU/EHA can directly replace the TIWAY I Host Adapter in single host
network applications. However, the MHIU/EHA cannot be used in a multiple
host
software

2.3.6

The Standalone Network Manager Mode

The Standalone Network Manager mode operates independent of any host
computer. It controls the TIWAY I network, but cannot accept any host
commands to change any performance parameters. You can use this mode to
implement
TIWAY I Host Adapter. Only minor changes to the applications software are
needed to process the adapter configuration command. A typical network is
shown

Emulate Host Adapter Modes

code 03, is not available in the HIU/EHA mode. Both of these modes

network. The HIU/EHA provides the ability to use TIWAY I Host Adapter

applications in a multiple host network.

a multiple host network using applications software written for the

in Figure 2–10.

UNILINK

(SANM)

Host
Com­puter

UNILINK

(HIU)

Host
Com­puter

(HIU)

Figure 2–10 Standalone NM Network

2.4 TIWAY I HOST SOFTWARE SUPPORT

As mentioned in Paragraph 2.3.5, the MHIU/EHA and HIU/EHA modes will
operate with the TIWAY I HOST SOFTWARE products. The MHIU and NM
modes

will also work with this product; however

and

NM commands in the XP

AR subroutine.

, you must enclose the extended

UNILINK

UNILINK HOST

USER MANUAL

ADAPTER 2–10

OPERATION

AND

APPLICATION

TIWAY I Host Software can be used with adapters in a
However,
CONFIGURE

you must define an HIU address using the XP

HIU command, and you cannot use the POLL command.

multiple host network.

AR subroutine and the

UNILINK HOST

USER MANUAL

ADAPTER2–11

OPERATION

AND

APPLICATION

2.5 SETTING THE OPERATING MODE

Each adapter must be configured for one of the six possible operating modes.
The mode is configured with the CONFIGURE ADAPTER command with the
exception of the Standalone NM mode, which is chosen by setting Positions 9
and

10

of Dipswitch 1 down. The defaults and dipswitch settings are discussed
further in Paragraph 2.5.1. There are three configuration commands; the
CONFIGURE
CONFIGURE

ADAPTER command, the
NM command.

CONFIGURE HIU command, and the

2.5.1

Configuration Defaults and Dipswitch Settings

Most of the parameters associated with the configuration commands have
default values chosen to help you install an operating host interface with a
minimum amount of effort. As your network expands and you gain experience
with

the advanced commands, you can change the defaults to tailor the network

performance
The adapter has two 10-position dipswitch banks, located behind the front

access door as shown in Figure 2–11. Most of the settings on the dipswitches
relate

to the parameters for the host and TIWAY I ports. However
Position
up, the adapter will default to an HIU/EHA and when Position 9 is down, the
adapter

to your needs.

, the setting of

9 on Dipswitch 2 determines the default mode value. When Position 9 is

will default to an MHIU/EHA.

Number 1

2

LEDsResetNumber

2.5.2

UNILINK HOST

USER MANUAL

Figure 2–11 Dipswitch Positions

The

default mode will be chosen when you issue one
before issuing the CONFIGURE ADAPTER command. In the later case, the
adapter
and
issue
or

The CONFIGURE ADAPTER Command

The first command your application software should send is the CONFIGURE
ADAPTER

ADAPTER 2–12

assumes the

assumes the EHA mode. This means that after the adapter is reset, if you

any of commands 01 through 08, the adapter will assume the MHIU/EHA

HIU/EHA mode depending on the setting of Position 9.

command, code 20. The main function of this command is to set the

default mode from the setting of Position 9 on Dipswitch 2

of the Base HIU commands

OPERATION

AND

APPLICATION

operating
set with this command is the Standalone Network Manager (SANM), since it
can not accept any host computer commands. Instead, the SANM mode is
selected
computer must send this command to its attached UNILINK Host Adapter(s).
The mode remains in effect and can not be changed until the adapter is reset.
The parameters for this command specify the HIU address, the maximum
secondary

mode to the value specified. The only operating mode that can not be

by

dipswitch settings described in Chapter 3 and Chapter 4. Each host

device address, and the macro memory limit.

UNILINK HOST

USER MANUAL

ADAPTER2–13

OPERATION

At

any

time, your applications software can retrieve the current values for these
parameters
code 21. In addition to those parameter values, this command will also return
the values of the dipswitch settings and a flag that indicates whether the
CONFIGURE

The physical network parameters for the HIU function of an MHIU are not
used, but the CONFIGURE ADAPTER command must still be sent to enable
the

HIUs network interface.

by issuing the REPORT ADAPTER CONFIGURA

ADAPTER command was previously processed.

AND

APPLICATION

TION command,

2.5.3

2.5.4

The CONFIGURE HIU Command

The CONFIGURE HIU command defines the network parameters for an HIU
function and enables the HIUs TIWAY I interface for both an MHIU and an
HIU.

The options and associated parameters can occur in the command string

in

any

order

, but they can not occur twice in the same command. This command
can only be issued once and if successful, the command code, 11, will be
returned.

The REPORT HIU CONFIGURATION command, code 12, will return the
values of the dipswitches, HIU Options, and a flag indicating whether the
configuration

The CONFIGURE NETWORK MANAGER Command

The CONFIGURE NETWORK MANAGER command, code 30, defines the
operating parameters for the network ports in the NM and MHIU modes and
specifies

Issue the REPORT NETWORK MANAGER CONFIGURATION command,
code 31, to retrieve the dipswitch settings and the current values for the
Network Manager parameters and to determine if the CONFIGURE
NETWORK MANAGER command has been processed. In a multiprocessing
environment,
whether

has been performed.

network options such as auto redundant media.

the tasks can check the configuration processed flag to determine

or not they can begin issuing commands to the adapter

.

UNILINK HOST

USER MANUAL

ADAPTER 2–14

OPERATION

AND

APPLICATION

2.5.5

Configuring the Standalone Network Manager

The

Standalone Network Manager (SANM)

dipswitch

settings. The

definition for some of the dipswitch positions is different

mode is configured completely with

for this operating mode as shown in Figure 2–12. The SANM mode is selected by
defining the host command timeout as zero by setting Positions 9 and 10 of
Dipswitch 1 down. The other positions of Dipswitch 1 define the TIWAY I
network

parameters.

DIPSWITCH 1

1

2345678910

U
P

MSB LSB

UP = SYNCHRONOUS
DOWN = ASYNCHRONOUS

UP = FULL DUPLEX
DOWN = HALF DUPLEX

UP = NRZI
DOWN = NRZ

DEFAULTS TO NITP

HOST COMMAND

TIMEOUT = 0

TIWAY I BAUD RATE

TIWAY I

TIWAY I

TIWAY I

DIPSWITCH 2

1

2345678910

U
P

UP = TEST MODE
DOWN = RUN MODE

MSB

LSB

UP = HIU/EHA &

DOWN = MHIU/EHA

UNUSED

UP = AUTO

DOWN = NO REDUNDĆ

HIU/NM BUFFERS

UP = DISC
DOWN = NO DISC

UP = AFTER CTS

DOWN = NO DELAY

IO LOOP TEST

REDUNDANT

MEDIA

ANT MEDIA

DELAY

Figure 2–12 Standalone Network Manager Dipswitch Settings

UNILINK HOST

USER MANUAL

ADAPTER2–15

OPERATION

Since

the SANM cannot accept any NM commands, Positions 1–7

define

certain Network Manager function options normally configured with the

CONFIGURE

NETWORK MANAGER command.

When

Position 1 of Dipswitch 2 is

after

CTS is active. No delay is selected when the dipswitch is down.

When

Position 2 of Dipswitch 2 is up, all
issue a network disconnect (DISC). This permission is granted by the
NM function when it initializes the HIU. No HIUs will be given
permission

to issue a DISC when the dipswitch is down.

AND

APPLICATION

of Dipswitch 2

up, it selects a one-half second delay

HIUs are given permission to

2.5.6

Positions
of NM buffers to assign to an HIU when the HIU is initialized. The
number
selected
significant bit and Position 6 is the least significant bit. The adapter will
then

When Position 7 of Dipswitch 2 is up, the NM function will use the
redundant
communicate

Configuration Summary

The general procedure for configuring the adapter follows in the list below

1.

Set the dipswitch positions.

2.

Issue the CONFIGURE ADAPTER command.

3. Issue
or

a NM)

4. Issue the CONFIGURE HIU command. (If this adapter will be an
MHIU

3–6 of Dipswitch

of NM buffers can range from 1 to 16. The actual binary value
will range from 0000 to 1111 binary where Position 3 is the most

add 1 to the binary value to scale the actual range to 1–16.

media feature that uses both network ports, Ports 1 and 2, to

with the secondary devices.

the CONFIGURE NM command. (If this adapter will be an

or an HIU)

2 represent the binary value for the number

MHIU

.

UNILINK HOST

USER MANUAL

ADAPTER 2–16

OPERATION

AND

APPLICATION

2.6 SPECIAL NETWORK MANAGER FEATURES

The adapter provides two special features in the MHIU and NM operating
modes.
channel switching. Second is the background monitor that will bring devices
online

First is the redundant media channels with selectable automatic media

dynamically

.

2.6.1

Redundant Media Channels

The

adapter provides for two network media channels, Ports 1 and 2, described

in

more detail in Chapter 4 . Y
specifying the
command. Using redundant media increases the mission reliability of the
network or the probability that the network will remain operational when a
random
Channel A or Port 1. Your applications software can then issue the SWITCH
CHANNEL command at any time to change the operating channel for one,
several,
redundant media feature is not active; however, if it is active, the Network
Manager
Port

2 must be available or an ERROR RESPONSE will be returned when you
try to issue this command.
the

command code and the channel code.

The primary function of redundant media is to provide a second
communications
be used as a maintenance aid by switching all secondaries to the alternate
channel so that the main channel can be maintained without completely
shutting the network down. Remember, only one media or channel can be
transmitting

appropriate value in the CONFIGURE NETWORK MANAGER

failure occurs. When first initialized, the adapter

or all secondary devices. The channel can be switched even if the

function will switch the channel back if a failure occurs. Channel B or

path in the event of a failure on the primary path. This can also

or receiving in a given instance.

ou may select to use only one channel or both by

will communicate on

auto

If the command is accepted, the adapter will return

The auto redundant media feature allows the Network Manager function to
automatically switch a secondary device to the opposite channel if
communications
device will be switched if it fails to respond consecutively in
maximum-retry-count times. The maximum retry count is specified in the
CONFIGURE
the secondary has been switched, the Network Manager function will attempt
to

communicate again on the new channel up
secondary responds, communications will continue on this channel. If the
secondary fails to respond, the secondary will be logged as off-line and all
associated macros will be disabled. All macro response status words will be
updated to indicate that the secondary is off-line, and any network requests
that

were pending will return the ERROR RESPONSE.

2.6.2 Backgr

Background monitor is a feature of the Network Manager that instructs it to
periodically check the link status of each secondary device. This feature is
active in the Network Manager function in all but the EHA modes and the
SANM mode. The link status information includes
for each channel and for each secondary, whether the secondary is online or

can no longer continue on the current channel. The

NETWORK MANAGER command and defaults to 3 times. Once

to the maximum retry count. If the

ound Monitor

the communications status

UNILINK HOST

secondary

ADAPTER2–17

USER MANUAL

OPERATION

AND

APPLICATION

offline,
through
directives or responses. In addition, it will also select one secondary device
address
initially begins with secondary number one and continues with the next
secondary address number until reaching the maximum secondary address
specified in the CONFIGURE ADAPTER command. Background monitoring
then

The current link status determines what action to take when monitoring a
device. If the current link status for the selected secondary address is offline,
the Network Manager will issue the initialization sequence. If there is no
response, the Network Manager will assume that the device is not in the
network and will not retry the message. If the device does respond, its status
will
time
online.

and if the secondary is an HIU. The Network Manager normally cycles

the secondary device log and checks to see if there are any outstanding

per cycle to perform a

starts over again with address one.

be updated and if it is an HIU, buffers will be allocated. This means that any

that a valid secondary device is connected to the

link status check. The selected secondary address

network, it will be brought

UNILINK HOST

USER MANUAL

ADAPTER 2–18

OPERATION

If the background monitor detects a secondary that went offline and the auto
redundant media feature is active, the Network Manager will attempt to
contact the secondary on the alternate channel as described in the Redundant
Media

section above.

You can obtain peak performance by consecutively numbering your secondary
devices and HIUs, starting with address 01, and by setting the largest
secondary
will keep the Network Manager from spending time on device addresses that
will
status
code

device address value in

never exist on

information with the REPORT SECONDARY LINK STATUS command,

32.

the network. Y

AND

APPLICATION

the CONFIGURE ADAPTER command. This

our applications software can request the link

UNILINK HOST

USER MANUAL

ADAPTER2–19

OPERATION

AND

APPLICATION

2.7 THE HIU AS A SECONDARY

The

HIU function appears as a special secondary device to the NM function. In
addition to queuing network requests for the NM function to process, the HIU
function will respond to TIWAY I Primitives 02 — Machine Status, 03 —
Machine Type/Configuration, and 04 — Primitive Format Configuration. The
TIWAY I Systems Manual provides more details on the format and use of
Primitives.

2.7.1 Primitive

The Primitive 02 response will be returned as follows (spaces were added for
clarity).

Where

Status is not available,

02 Response

LLLL

02 HH DD EE FF

LLLL is the Primitive length,

HH will be 00 indicating that it is operational and
performing instruction execution,

DD will be 01 indicating that the Auxiliary Power Source

EE will be 00 indicating that the NIM is operational,

FF will be 00 and has no meaning for an HIU.

UNILINK HOST

USER MANUAL

ADAPTER 2–20

OPERATION

AND

APPLICATION

2.7.2

2.7.3

Primitive 03 Response

The Primitive 03 response will be returned as follows.

LLLL 03 HH DDDD EEEE FFFF GGGG IIII JJJJ KKKKKKKK

Where

Primitive 04 Response

The Primitive 04 response will be returned as follows.

LLLL is the Primitive length,

HH will be 00 indicating that it is operational and
performing instruction execution,

DDDD will be 007E indicating that the device type is
an HIU,

EEEE, FFFF

KKKKKKKK will be 00000000.

LLLL 04 NNNN MM EE FF GG

, GGGG, IIII, JJJJ will be 0000,

Where

LLLL is the Primitive length,

NNNN will be 010E and indicates the maximum Primitive
length supported,

MM, EE, FF

, GG will be 00.

UNILINK HOST

USER MANUAL

ADAPTER2–21

OPERATION

AND

APPLICATION

2.8 MODE INDEPENDENT OPERATIONS

The

mode independent commands perform hardware and software resets,
external I/O point operations regardless of the operating modes.

and

2.8.1

Reset Commands

There

are two reset commands that can be sent to the UNILINK Host Adapter
regardless of the operating mode. The reset commands should be used
cautiously because they clear all macros and configuration parameters, and
discard any outstanding operations on the network. The first is the SOFT
RESET command, code FE. This command causes the adapter to execute a
software
adapter will go into a startup state without performing power up diagnostics.
The command code will be returned as a response and the reset will begin
immediately
should

The second reset command is the RESET ADAPTER command, code FF. The
reset
to the host. Your applications software should allow an additional five second
delay

The
polled when using the host BDLC protocol. Chapter 3 provides more
information

reset operation. All current TIWAY I operations

after sending the response to the host. Y

not issue another command for at least 500 ms.

will begin within one second after the reset command response is returned

before issuing another command to allow the diagnostics to complete.

response to either reset command will not be returned until the adapter is

on host interface protocols.

will be aborted and the

our applications

software

UNILINK HOST

USER MANUAL

ADAPTER 2–22

OPERATION

AND

APPLICATION

2.8.2 The Exter

The UNILINK Adapter provides a single external input point and a single
external
in a variety of applications like a remote “Adapter Good” indicator. For safety
critical applications, any external alarms should be hard-wired independently
of

the P/C.

Figure 2–13 External Input/Output Points Example Application

nal Input/Output Points

output point. These two points operate independently and can be

Panel
Lamp

20 – 40 VDC
20 – 36 V
(RMS)

AC

UNILINK Host
Adapter

IN OUT

Remote
“ADAPTER GOOD”
Indicator

used

UNILINK HOST

USER MANUAL

ADAPTER2–23

OPERATION

AND

APPLICATION

2.8.2.1 The

The input point latches a high level. The option parameter of the REPORT
EXTERNAL
external

Options 00 and 01 report whether the “on” condition ever occurred, but not
report
the instantaneous value of the input and should be used for time dependent
applications.
indicating that the input is on. The complete specifications for the input point
are given in the UNILINK Adapter Installation and Operation Manual
(TIWAY–8106).

2.8.2.2 The

The MODIFY EXTERNAL OUTPUT STATUS command either turns the
external
given in the UNILINK Adapter Installation and Operation Manual
(TIWAY–8106). The command code FC, along with either 00 or 01 will
respectively turn off or turn on the output point. The adapter will return the
command
after
point by connecting it to a remote control center panel lamp so that when the
host computer applications software issues the MODIFY EXTERNAL
OUTPUT
problem

Exter

nal Input Point

INPUT STATUS command determines when to reset and latch the

input. The values for the command option are:

00 = Read the input, do not reset the latch.

01 = Read the input, then reset the latch.

02 = Reset the latch, then read the input.

the current state of the external input point. Option 02, however, reports

The response will be either 00 indicating that the input is off, or

Exter

nal Output Point

output point ON or turns it OFF

code in

a reset or power

STATUS command to turn on the output point, the lamp will light. If a

occurs that causes the adapter to reset, the lamp will be extinguished.

response. The initial state of the External Output Point is zero

-up. A remote “Adapter Good” lamp can be set up using this

. The corresponding voltage levels are

01

UNILINK HOST

USER MANUAL

ADAPTER 2–24

OPERATION

AND

APPLICATION

2.9 BASIC NETWORK OPERATIONS

The simplest network operations, in either a single or multiple host network,
are performed using the Base HIU commands, codes 1–8. These commands
allow you to bring secondary devices online and offline, send data to/from the
secondaries,
issue requests, meaning that the host application must wait for the network
response
to

process multiple outstanding transactions.

and retrieve basic statistics. However

before another command

can be issued. Paragraph 2.10 discusses how

, these commands are direct

2.9.1

Bringing Secondary Devices Online

Issue the CONNECT SECONDARY command to bring secondary devices
online. This command logically connects one or more secondary devices and
allows your applications software to selectively connect the secondary devices
on the network. Memory space will be allocated for secondary device statistics
the first time that the secondary is connected. This space will remain in use
until

the adapter is reset.

The

address value FF hex or 255 decimal has been reserved as a global address

that

will connect all secondaries up to the largest address value, specified when
the adapter was configured. You must be careful when requesting multiple
secondary connections. If the responses are not received before the host
command
to issue the READ SECONDARY LOG command to determine which
secondaries were connected before the timeout. A successful connection will
return
connected successfully
be

the command code and a 00 address value.

timeout, the ERROR RESPONSE will be returned and you will have

the command code and a list of the secondary device addresses that were

. If no address in the list was connected, the response will

NOTE

The host computer must wait for the response to be
returned for the CONNECT SECONDARY and
READ

SECONDAR

Y LOG commands before

issuing
another command, regardless of the adapter
operating

mode. There can be

a long time delay when

using the special global address (FF hex).

UNILINK HOST

USER MANUAL

ADAPTER2–25

OPERATION

AND

APPLICATION

2.9.2 Sending

After the secondary device is connected, your applications software can send
TIWAY I Primitives to the secondary with the SEND NETWORK DATA
command or the BROADCAST NETWORK DATA TRANSFER command. The
TIWAY
elements, controlling the operating mode, and testing the status and
configuration

The SEND NETWORK DATA command transfers a TIWAY I Primitive to a
specified secondary device. When completed, the adapter will return the
command

Data To And Fr

I Primitives provide control functions such as reading and writing data

of the secondary devices.

code, the secondary address, and the Primitive response.

om Secondary Devices

NOTE

The host computer must wait for the response to be
returned for the SEND NETWORK DATA and
BROADCAST NETWORK DATA commands before
issuing another command, regardless of adapter’s
operating mode.

UNILINK HOST

USER MANUAL

ADAPTER 2–26

OPERATION

The BROADCAST NETWORK DATA TRANSFER command will send the
Primitive to all logically connected secondary devices on the network and is
provided for backward compatibility with the original TIWAY I Host Adapter.
The

Broadcast/Poll sequence is more efficiently handled with macros discussed
in Paragraph 2.10. Unlike the SEND NETWORK DATA command, the
responses
accepted, the command code will be returned, then your applications software
MUST issue a POLL command to each secondary to collect the Primitive
response.

from the secondaries do not automatically return. If

AND

APPLICATION

the command is

CAUTION

You should not issue the BROADCAST
NETWORK

DATA TRANSFER command if

your
network contains Intelligent Tank
Transmitters (ITTs) as secondary devices or
you could loose responses. Also, sending a
BROADCAST NETWORK DATA TRANSFER
command when your adapter is configured as
either an MHIU or an HIU will cause an
network

HDLC error to be logged even though
the information was received. This error will
be included in the statistics from the READ
SECONDARY DIAGNOSTICS, REPORT HIU
STATUS, REPORT NETWORK MANAGER
SECONDARY STATISTICS and the REPORT
NETWORK MANAGER NETWORK
STATISTICS commands.

The POLL command can only be used by an adapter configured as an
MHIU/EHA,
operating modes with macros. Example 2–1 is a typical sequence for the
broadcast/poll

however

commands.

, the broadcast/poll sequence can be implemented in other

UNILINK HOST

USER MANUAL

ADAPTER2–27

OPERATION

AND

APPLICATION

2.9.3 Retrieving

The UNILINK Host Adapter maintains network statistics for the logically
connected secondaries on the network. This information is not essential for
normal

operation, but can be useful for identifying problems.

02 0002 11 00
02
03 01
03 01 0002 11 01
03 02
03 02 0002 11 01
03 03

Issue Broadcast command
Accepted response
Poll address #1
Address #1 response
Poll address #2
Address #2 response
Poll remaining addresses

Example 2–1 BROADCAST/POLL Example

Secondary Statistics

The

first statistical command is the READ SECONDARY LOG command, code

06. When this command is received, the UNILINK Host Adapter will respond
with

the command code followed by the list of secondary device addresses that

are

logically connected. If no secondaries are connected, the list will contain one

byte

with a value of 00.

The second command is the READ SECONDARY DIAGNOSTICS command.
This command returns statistical counters for the network HDLC
transmissions and errors. Along with the command code and secondary
address, there is a reset statistics counters parameter. The counters are not
automatically reset when their maximum value is reached. The reset
parameter allows your applications software to reset the counters to start a
baseline

measurement.

UNILINK HOST

USER MANUAL

ADAPTER 2–28

OPERATION

AND

APPLICATION

2.9.4 T

2.9.5

aking Secondary Devices Of

The

DISCONNECT SECONDARIES
of the CONNECT SECONDARIES command. The secondary devices listed
after

the command code are logically disconnected and their addresses removed
from the secondary log. Again, the special address code FF, instructs the
UNILINK Host Adapter to attempt to disconnect all logically connected
secondaries. You must be careful when disconnecting more than one secondary
device. The command may be aborted if all secondaries are not disconnected
before

the host command timeout expires and the ERROR RESPONSE will be
returned.
secondaries that disconnected properly
connected,

The HIU function must have permission to issue a disconnect to a secondary
before
the secondary device will be removed from the secondary log, but will remain
online. Option–09 of the CONFIGURE NETWORK MANAGER command
defines
addition, the ALLOCATE NETWORK MANAGER BUFFERS command can
specify

Retrieving Adapter Statistics

The normal response returned will be the command code and a list

the response will be the command code and a 00 address value.

the secondary is actually taken offline. If the permission

the default for granting this permission by the background monitor

the permission.

f-line

command performs the opposite function

of

. If none of the addresses in the list were

is not granted,

. In

The READ ADAPTER DIAGNOSTICS command, code 08, is another aid to
identifying processing problems. This command retrieves a list of counters
indicating the number of times that each Base HIU command has been
processed.
often
statistics,
of

is reached.

This will help build a profile of which commands

and will indicate possible bottlenecks. Like the counters for the secondary

these counters are not automatically reset when the maximum limit

are processed most

UNILINK HOST

USER MANUAL

ADAPTER2–29

OPERATION

AND

APPLICATION

2.10 EXTENDED NETWORK OPERATIONS

The Extended HIU (EHIU) commands provide several performance
improvement

benefits through macros and bandwidth adjustments.

2.10.1

2.10.1.1

What Ar

Normally, when the host computer issues a network request to connect,
disconnect, and send data to and from secondary devices, it must wait for the
response to be returned. Macros are network requests that are stored and
scheduled for independent processing by the HIU function. The HIU function
will issue the network request at the proper time and store the response. This
frees the host computer to issue other commands and retrieve request
responses without the burden of real-time host computer control. The HIU
function is free to schedule macro transmissions and collect responses, so that
new macro requests can be issued to the NM function while waiting for older
ones to complete processing in the secondary devices. This keeps the network
efficient

Configuration Modes Supporting Macr

e Macr

and increases data throughput.

os?

os

Table 2–1 Configuration Modes Supporting Macros

Macros supported?

MHIU
EHA

No

HIU
EHA

No

MHIU

Yes

HIU

Yes

NM

No

NM
SA

No

UNILINK HOST

USER MANUAL

The UNILINK Host Adapter must be configured as either a Master Host
Interface Unit or a Host Interface Unit to use the macro feature. These two
operating modes accept the extended host commands for defining macros and
collecting macro responses. Macros are not supported in the Emulate Host
Adapter

ADAPTER 2–30

modes.

OPERATION

AND

APPLICATION

2.10.1.2

Repetitive and Non-Repetitive Macr

You specify in each macro definition whether the macro should be issued one
time or repeated at regular time intervals. Non-repetitive macros are issued

and collect one macro response, functioning much like

once
To reissue the non-repetitive macro, your applications software only needs to
send the ENABLE/DISABLE MACRO EXECUTION command to enable it,
saving the host-to-adapter communications overhead of sending the
data

again.

Repetitive macros are issued at the specified time intervals with each new
macro response replacing the previous response. The macro will be repeated
until your applications software sends the ENABLE/DISABLE MACRO
EXECUTION
are

scheduled for processing by the HIU function.

The HIU function schedules the requests in the following order:

1.

2.

3.

4.

command to disable it.

Direct commands for a single secondary device
Direct commands for multiple secondary devices
Non-repetitive macros
Repetitive macros

os

a direct command.

Primitive

Both repetitive and non-repetitive macros

The HIU function queues all requests except the direct commands for single
secondaries. A single secondary direct command is given a higher priority and
will

be sent to the NM function before any of
scheme prevents the repetitive macros from using the entire network
bandwidth.

When

the ENABLE/DISABLE MACRO EXECUTION command code is issued,
the non-repetitive macros will be sent in the order listed in the command
parameters.
the non-repetitive macros. Repetitive macros can be used for background data
acquisition, freeing the host computer application even further. Each new
repetitive macro response is compared to its previous response and if a
difference
application
the overhead of collecting and comparing the macro responses itself. A Freeze
Exception option can be specified when defining the repetitive macros. This
option will disable the macro execution when the exception is detected, and
freeze

The provides a method for defining your own execution priority for

is detected,

can check the state of the exception flag and

the data that caused the exception.

the exception flag for that macro is set. The host computer

the queued requests. This priority

act accordingly without

UNILINK HOST

USER MANUAL

ADAPTER2–31

OPERATION

AND

APPLICATION

2.10.2

The Parts of a Macr

o

MACRO HEADER

MACRO COMMAND BUFFER

MACRO RESPONSE BUFFER

Figure 2–14 The Parts of a Macro

Each

macro is stored in a variable length buffer
by a unique buffer number assigned by the HIU function when the buffer is
allocated.
to 254 buffers can be allocated, depending on the size of each macro and the
amount
command and response buffers referenced by the same unique buffer number
and
command buffer and its corresponding macro response buffer in the
ALLOCATE MACRO BUFFER command. Use the following formula to
calculate

This buffer number ranges from 1 to 254 (01 hex to FE hex) so that up

of memory set aside for the macro buffers. Each macro

a macro header as shown in Figure 2–14. You specify the size of each macro

the number of bytes of memory required for each macro:

. The macro buffer is referenced

buffer consists of

Macro Memory = 22 Bytes + Macro Command + Macro Response

(Header)

If this total is an odd number of bytes, add one to make the total count even.

The

header is a storage area
the Macro Response Status Word (MRSW). The MRSW is normally a counter
that

holds the number of times a repetitive macro has
if an error or exception occurs, a termination code indicating the cause of the
error

will be stored there.

get

the MRSW

address

associated with the macro, and internally used pointers and flags.

value. The header also contains the Source Id and the secondary

for the macro operating parameters, one of which is

Send the GA

Buffer Length Buffer Length

been executed. However

THER MACRO RESPONSE command to

,

UNILINK HOST

USER MANUAL

ADAPTER 2–32

OPERATION

AND

APPLICATION

The total macro memory requirements can be calculated by summing the
memory for each individual macro. For example, suppose that you use one
macro

to connect secondary #7, another macro to issue a Primitive 45 bytes long
expecting
#5.

a response 30 bytes

long, and another macro to disconnect secondary

The total memory required for these three macros is:

Macro #1, Connect
Macro #2, Primitive
Macro #3, Disconnect

T

otal Memory Required

= 22 = 22
= 22 + 45 + 30
= 22 = 22

= 97(+1)
22



142 Bytes

Example 2–2 Macro Memory Requirements

Host
Computer

UNILINK

TIWAY

I

UniLink Host Adapter

22
98

Job Directory
Job A
Job B
Job C

Figure 2–15 Host Computer Multiprocessing Application

Example

UNILINK HOST

USER MANUAL

ADAPTER2–33

OPERATION

The UNILINK Host Adapter also supports multiprocessing in host computer
applications through the host assigned Source Identification number. This
number associates each host task with corresponding macros, preventing one
task from interfering with another’s resources. Up to thirty-two independent
host

tasks can be in use at any one time, each assigned a unique value, from 1 to

254. The Source ID can also be used in single task environments to group
related

subtasks and gather their responses.

AND

APPLICATION

2.10.3

The Macr

Macros are defined and maintained with the following commands.

o Commands

 ALLOCA
 ALLOCA



DEFINE MACRO

 GA



ENABLE/DISABLE MACRO EXECUTION



INITIALIZE MACRO RESPONSE BUFFER



LINK MACRO

TE SOURCE ID
TE MACRO STORAGE BUFFERS

THER MACRO RESPONSE

UNILINK HOST

USER MANUAL

ADAPTER 2–34

OPERATION

AND

APPLICATION

2.10.4

Setting Up A Macr

Figure
available memory are not included in the flowchart, but are described in the
sections

2–16 flowcharts the steps for setting up macros. Commands for checking

that follow

o

.

Allocate A
Macro Buf

Define the Macro

More Macros
for the same
source?

(START)

Allocate A
Source ID

fer

Yes

No

(END)

Figure 2–16 Macro Setup Procedure

UNILINK HOST

USER MANUAL

ADAPTER2–35

OPERATION

AND

APPLICATION

2.10.4.1 Allocate

Use the ALLOCATE SOURCE ID command, code 10, to specify a Source
Identification number which can range from 1 to 254 (01 to FE hex). Only
thirty-two unique Source Identification numbers can be used at any one time.
Figure

2–17 illustrates the relationship between Source Ids and macro buffers.

Source
(OE)

A Source Identification Number

ID #1

Macro Buf
#1

Macro Buf
#35

Macro Buf
#63

Macro Buf
#87

fer

fer

fer

fer

Source ID #2
(1A)

Macro Buf
#2

Macro Buf
#3

Macro Buf
#80

Macro Buf
#97

Macro Buf
#109

fer

fer

fer

fer

fer

Source ID #32
(E5)

Macro Buf
#4

Macro Buf
#33

Macro Buf
#60

fer

fer

fer

Up to 32
unique
source
IDs

Up to 254
Macro
Buffers

Figure 2–17 Relationship Between Source Ids and Macro

Buffers

UNILINK HOST

USER MANUAL

ADAPTER 2–36

OPERATION

If this command is accepted, the UNILINK Host Adapter will echo back this
same command string, otherwise the ERROR RESPONSE will be returned.
Source Ids can also be used to group network responses, such as the status of
each device. Only one Source Identification number is allocated with each
command

sent to the UNILINK Host Adapter

AND

APPLICATION

.

WARNING

All existing macro buffers for the Source
Identification

number

will be cleared when the
ALLOCATE SOURCE ID command is
processed. This prevents a task that
abnormally terminated from allocating
additional resources while the original
resources remain allocated, but unused. Make
sure that your application programs use
unique Source Identification numbers.

2.10.4.2 Allocate

Use the ALLOCATE MACRO STORAGE BUFFERS command, code 13, to
define

and specify the length for both the macro command buffer and the macro
response buffer. The UNILINK Host Adapter will return the buffer number
assigned by the HIU. Store the buffer number in your application program
later

reference. If you specify more than one buffer pair in the command, more
than one buffer number will be returned in the response. Be sure to allocate a
sufficient
response buffer.

The Macr

length of memory

o Buf

fers

for

for both the macro command buffer and the macro

UNILINK HOST

USER MANUAL

ADAPTER2–37

OPERATION

AND

APPLICATION

2.10.4.3

Define The Macr

the DEFINE MACRO command,

Use
options.
connect
These
and “disconnect” secondary macro types do not require any buffer storage to
hold

14

Figure 2–18 shows the DEFINE MACRO command frame. Macros can

a secondary

three functions are the macro types as shown in T

the command, only 22 bytes for the header

Source Buffer Secondary Macro Options

o

code 14, to define the macro and the macro

, disconnect a secondary

Id # Address Type Byte

, or send a Primitive to a secondary

.

able 2–2. The “connect”

Minimum

Reissue

Delay

Primitive

Data

Figure 2–18 Macro Command Frame

T

able 2–2 Macro Types

Type

Code

Function Performed

.

01
02
03

The UNILINK Host Adapter will return the Command Code, the Source
Identification number, and the buffer number to indicate that the command
was accepted. However, this does not mean that the secondary was actually
connected because macros are scheduled for later execution. When the
“connect”
connect
type works just like the “connect” secondary type except that the secondary is
disconnected rather than connected. Both the “connect” and “disconnect”
secondary macro types are automatically enabled for execution when the
command

secondary macro is executed, the MRSW will be set to indicate if the

was successful or if not,

is accepted from the host computer

Send Primitive to secondary
Connect the secondary
Disconnect the secondary

why it failed. The “disconnect” secondary macro

.

UNILINK HOST

USER MANUAL

ADAPTER 2–38

OPERATION

The third macro type is “send Primitive” which is functionally equivalent to
using the SEND NETWORK DATA command, but is far more flexible. This
macro

begins with the same bytes as the two other types with the addition of a
macro options byte, a minimum reissue delay time word, and the Primitive
data. The macro options byte uses its five most significant bits to enable or
disable

the following options.

AND

APPLICATION

 The

 The repetitive/non-repetitive option which defines how the macro will

 The freeze option which selects whether to freeze the macro and

 The

Unlike the two other macro types, the “send Primitive” macro type is not
implicitly enabled for execution. You must set Bit 0 to a value of 1 or use the
ENABLE/DISABLE
scheduled
first

macro response received for an exception. When the macro response buffer

is

first allocated, its contents are undefined which will cause the first response
received to set the exception flag. Setting Bit 4 will prevent this exception, or
you can initialize the contents of the macro response buffer with the
INITIALIZE MACRO RESPONSE BUFFER command. Example 2–3 shows
examples

auto enable option which specifies whether to automatically enable

the

macro for execution after
choose this option, you can explicitly enable the macro with the
ENABLE/DISABLE

be

executed.

response

flag

for execution. The last option, Bit 4,

of the bit coding for various combinations.

when an exception occurs.

set first
on the first response.

exception option which selects whether to set the exception

MACRO EXECUTION command before the macro will

MACRO EXECUTION command.

definition is complete or not. If you do not

be

causes the HIU to not check the

UNILINK HOST

USER MANUAL

ADAPTER2–39

OPERATION

MSB LSB Byte ACTIONS

(hex)

0

0 0 0 0 0 0 0 = 00
1 1 0 0 0 0 0 0 = C0
0 1 1 1 0 0 0 0 = 70

AND

APPLICATION

Non-repetitive, must be explicitly
enabled,
Repetitive, auto enabled, will not
freeze exception
Repetitive, must be explicitly enabled,
will freeze exception data, will not
check first response for an exception

Example 2–3 Macro Options Byte — Bit Coding

The minimum macro reissue delay time word or double byte specifies the
number
time ranges from 0 to 30,000 milliseconds in 10 millisecond increments. This
option only specifies the minimum time to delay the macro and should not be
used for time dependent applications. Heavy network loading could cause the
macro

You can redefine a macro, but it must be disabled first with the
ENABLE/DISABLE
discard

of milliseconds to delay before reissuing a repetitive macro. The

to be delayed longer than this minimum delay

MACRO command, which will clear the exception flag

any outstanding responses.

.

delay

and

2.10.5

Checking The Macr

The GATHER MACRO RESPONSE command collects one or more macro
responses. You can choose to retrieve the entire macro response buffer data
along with the Macro Response Status Word (MRSW) or just the MRSW. You
can also choose to retrieve all the buffers specified or just those with their
exception flags set. In addition to the command code, specify the Source
Identification

The response type byte can be either code 00, 01, or 02. Code 00 instructs the
UNILINK Host Adapter to return all of the buffer data including the MRSW.
Code

01 will return all of the buffer data, but only for the requested buffers

their

exception flags set. Code
buffers
reset
01;

that have their

each time that the buffer data is retrieved with response type codes 00

it is not reset with response code 02.

number

o Response and Macr

, the response type, and the buffer number or numbers.

02 will return only the MRSW

exception flags set. The macro response exception flag is

o Status

with

, for the requested

and

UNILINK HOST

USER MANUAL

ADAPTER 2–40

OPERATION

You

can request more than one buffer at a time; however, be sure that the total
combined
length,
into

The secondary address, MRSW, Primitive data length, and the Primitive data
will
condition.
the
buffer data for the first buffer that has its exception flag set. This allows your
host

Table 2–3 describes the meaning for the different values of the MRSW. If the
macro terminated abnormally, the exception flag will be set and the
Termination
macro
host computer. Refer to Chapter 6 for a more detailed explanation of each
termination

length of

or the ERROR RESPONSE will be returned. The Primitive data must fit

one host response I-Frame.

be returned for

Specifying buffer number 00 is a special case that ignores the value in

response type byte. In this case, the HIU will return the buffer number

application program to receive any exceptions as they occur

is explicitly disabled or the secondary device has been disconnected by a

code.

each buffer response does not exceed the maximum message

each buffer number requested that meets the response type

Code will reflect the error

AND

APPLICATION

and

.

. The exception flag will also be set if the

MRSW V

(hex)

0000

0001

to

7FFF
8000

to

FFFF

Table 2–3 MRSW Values

alues

Description

This macro has not been executed
since the last time it was
enabled.

The number of times a repetitive
macro response has been updated.

T

ermination Code – the macro is
disabled due to either an error
exception, or an explicit disable.

, an

UNILINK HOST

USER MANUAL

ADAPTER2–41

OPERATION

AND

APPLICATION

2.10.6 Enabling

The ENABLE/DISABLE MACRO EXECUTION command explicitly enables
and/or

disables defined macros for execution. When this command is processed

the

exception flag will
being enabled, or the MRSW set to the disabled Termination Code 8001 hex if
the

macro is being disabled. Macros will only be enabled when their associated
secondary
for

that macro.

The adapter will return the ENABLE/DISABLE MACRO EXECUTION
command
bytes for each requested buffer number. The first byte in the pair is the
requested buffer number and the second byte is the response code which
indicates

2.10.7

Initializing the Macr

There are two ways to insure that only a valid exception will set
flag.

The first way was shown in the DEFINE MACRO command. By setting Bit
3 in the macro options byte, the first macro response will be received, but not
compared to the contents in the macro response buffer. Thereafter, the new
responses

and Disabling Macr

be cleared and the MRSW reset to 0000 hex if the macro is

device is online, otherwise, the ERROR RESPONSE will be returned

code,

the Source Identification number

whether the requested action was successful.

o Response Buf

will be compared to that first response.

os

fer

, and a list containing a pair of

the

exception

The second way is to store a predefined value in the macro response buffer by
using the INITIALIZE MACRO RESPONSE BUFFER command. A useful
application is to define a macro that retrieves the status information from a
secondary
operating manual for the secondary device gives the exact Primitive response
that should be returned for a status “OK”. Preload this value into the macro
response buffer. Then, the exception flag will be set when the response is
anything

The
the Source Identification number, the buffer number, the Primitive response
being preloaded, and an automatic enable byte. The macro must be disabled
before sending this command. The automatic enable byte can then be used to
enable the macro for execution after the response buffer is loaded without
having to issue a separate ENABLE/DISABLE MACRO EXECUTION
command.

device and sets the exception whenever the response is not “OK”. The

other than the “OK” status that was expected.

INITIALIZE MACRO RESPONSE BUFFER command

byte string includes

UNILINK HOST

USER MANUAL

ADAPTER 2–42

OPERATION

AND

APPLICATION

2.10.8 Checking

There

is a
will need to do for the flexibility provided by macros. Your programs should
apply

the following rules.

 Your

numbers.

 Your

numbers are active at a time. This is easily accomplished by
maintaining
to assign another Source Id number and have already assigned 32
Source Ids, you can deallocate one number and allocate another.
However, remember that deallocating a Source Id clears all macro
buffers associated with that Source Id, so you should retrieve any
outstanding

 Your programs must keep track of the buffer numbers and the

associated
by

 Your programs must ensure that no more than 254 macro buffers are

allocated.

Memory Usage

certain amount of housekeeping that your host application programs

programs must assign and keep

programs must ensure that no more than 32 Source Identification

an

internal table in your applications program. If you need

responses before deallocating.

Source Identification number

maintaining an internal table in your applications program.

track of the Source Identification

. This can

also be accomplished

2.10.9

The

REPORT MEMOR
items. When your program sends Command Code 18, the UNILINK Host
Adapter
the number of unallocated macro buffers, the number of unallocated Source
Identification numbers, and a list of all Source Identification numbers
currently

Linking Macr

In
form
Figure 2–19. Data types from one device will be retrieved from one secondary
and then transferred to the other secondary without any further host
intervention. The LINK MACRO command, code 1C, accepts a Source Id and
two
Id or an error will be returned. The first macro command buffer number
represents the the trigger macro. When the trigger macro is enabled and
completes processing, the second macro command buffer number or action
macro

will return the Command Code, the number of memory bytes

active.

os

addition to the basic operations with macros, you can also link two macros

a “store and forward” link between two

macro command buffer numbers. Both macros must have the same Source

will be executed.

Y USAGE command will help your programs track these

available,

to

secondary devices as illustrated in

UNILINK HOST

USER MANUAL

ADAPTER2–43

OPERATION

AND

APPLICATION

UNILINK Host Adapter
Macro Response Buf

Macro Response Buf

Data Packet

fer #A

fer #B

Data Packet

Secondary
#1

Secondary
#2

Figure 2–19 Link Macro Store and Forward Operation

Both macros must be disabled before the LINK MACRO command will be
accepted.
the secondary device. The action macro must be a valid Primitive 30 or B0 to
write the data read to the other secondary. All of the define macro options on
each macro command buffer are valid until the link is established. When the
link
link

The trigger macro must be a valid Primitive 20 or A0 to read data from

is established, the action macro will be considered non-repetitive. When the

is terminated the original conditions will be valid again.

UNILINK HOST

USER MANUAL

The adapter will check the validity of the host supplied Primitives before
linking
starting addresses (AAAA field of the Primitive). You must insure that the
number of TT types (NNNN field of Primitive) and the starting addresses are
valid

Once
The trigger macro behaves much like a non-linked macro, except that it is
disabled while the action macro executes. Each time the trigger macro
completes a read, the trigger macro is disabled, its data moved into the action
macro
the
enabled

ADAPTER 2–44

them. The

for both secondaries involved.

the link

buffer to create a valid write Primitive

trigger macro receives an error from the secondary, the action macro is not

and the exception flag is set disabling the trigger macro.

Primitives must use the same TT type, but may use different

is established, just enable the trigger macro to begin the process.

and the action macro is enabled. If

OPERATION

Once

the action macro has successfully completed, the trigger
though
trigger
that

The exception flag of the action macro is only set when an error occurs for its
secondary
the secondary is
macro will then execute as a non-linked macro. You will need to correct the
problem, then execute a recovery subroutine that will perform the following
steps.

the link never existed. If it is a repetitive macro, it will be enabled. The

macro’

it will not be set until the action macro has completed execution.

s exception flag is also set as though the link never existed except

device. If the action macro can not be executed for any reason, such as

offline, the link will be automatically terminated. The trigger

AND

APPLICATION

macro behaves as

2.10.10

2.10.10.1

1. Disable

2.

Reissue the LINK MACRO command.

3.

Enable the trigger macro to start executing the link again.

The link is not automatically terminated if the trigger macro fails.

Network Per

You

can improve the performance of your
of the HIUs. The statistical commands will provide a picture of transaction
bottlenecks that you can also adjust. One performance measure was already
discussed

Network Bandwidth

The

Network Manager serves as the primary in a TIWAY I network. It handles
all communications between HIUs and other secondaries. It uses Network
Manager buffers to temporarily store requests and responses before they are
forwarded to the appropriate devices. These buffers are divided between the
HIUs on the network. The number of buffers assigned to a particular HIU its
bandwidth. The more buffers allocated to the HIU, the more requests the
Network

Manager function can simultaneously process for that HIU.

the trigger macro.

formance

networks by adjusting the bandwidth

in Paragraph 2.6.2.

UNILINK HOST

USER MANUAL

ADAPTER2–45

OPERATION

AND

APPLICATION

2.10.10.2

NM Buf

These buffers are allocated implicitly with the background monitor function.
However, the NM function in an adapter in the MHIU/EHA mode does not
support background monitor or multiple hosts. The value specified for
Option–09 of the CONFIGURE NETWORK MANAGER command will be
allocated
was
buffers.

An
with the ALLOCATE NETWORK MANAGER BUFFERS command when the
number
the NM function is enabled by the CONFIGURE NETWORK MANAGER
command. The ALLOCATE NETWORK MANAGER BUFFERS command can
only be issued by the host computer attached to the adapter functioning the
Network
are

The adapter will return the command code and the HIU address if the
ALLOCATE NETWORK MANAGER BUFFERS command is accepted. Your
applications software can issue the REPORT NETWORK MANAGER
BUFFERS AV
To use it, send the one byte command, code 35. The adapter will return the
command
available.

fer Allocation

to each HIU function as the NM function brings it online. If no value

specified for Option–09, the value will default to one fourth of the

amount other that the default number of buffers can be allocated explicitly

of buffers allocated by the background monitor is zero or if issued before

Manager and can only be issued once for each as HIU. After the

allocated, they will remain allocated until the NM or MHIU is reset.

AILABLE command to determine how many buffers are unused.

code, the total number of NM buffers, and the number of NM buffers

available

buffers

UNILINK HOST

USER MANUAL

ADAPTER 2–46

OPERATION

AND

APPLICATION

2.10.10.3 Adjusting

The REPORT NETWORK BANDWIDTH ALLOCATION command, code 36,
returns counters that reflect the relative network activity for a specific HIU.
The counters do not reset after reaching their maximum value and must be
explicitly

Although the HIUs on the network have no direct control over the number of
Network
are used with the ALLOCATE HIU BANDWIDTH command. This command
defines
macros and repetitive macros by specifying how many of the allocated buffers
will
NM buffers allocated to the HIU. This command also limits the number of
outstanding requests for a single secondary device, preventing one secondary
from dominating the entire bandwidth. The default for this parameter is the
smaller
the HIU. Both parameters are single bytes ranging from 00 to the number of
NM buffers allocated to the HIU. The command code will be returned if the
command
than once in order to change the parameters to match the demands as they
change.

Issue
the buffer allocation and retrieve macro statistical counters. The statistical
counter parameters are long words that must be explicitly reset when they
reach
and

how the buffers are to be divided between direct requests/non-repetitive

be used for repetitive macros. By default, repetitive macros

of two requests per secondary or the number of NM buffers allocated to

the REPORT HIU BANDWIDTH ALLOCA

their maximum values. The command

the optional reset counters code.

An HIUs Bandwidth

reset.

Manager buffers allocated to them, they

is accepted. Y

our applications software may issue this command more

string includes the command code

can control how those buffers

can use all of the

TION command to

determine

There are two sets of counters, one for repetitive macros and the other for
non-repetitive macros. The first counter in each set counts the number of
I-Frame
set counts the number of I-Frame bytes sent by the macro type. The third
counter in each set counts the number of I-Frame bytes received by the macro
type. These counts do not include any HDLC overhead or communications
counts between the NM and the HIU. Reset these counters by sending the
command string 1A 01. The adapter will return the command code 1A if
accepted.

pairs sent and received by the macro type. The second counter in each

UNILINK HOST

USER MANUAL

ADAPTER2–47

OPERATION

AND

APPLICATION

2.10.10.4 Performance

The REPORT NETWORK MANAGER SECONDARY STATISTICS and
REPORT NETWORK MANAGER NETWORK STATISTICS commands are
provided as network diagnostic aids for locating bottlenecks or faulty
secondaries. The REPORT NETWORK MANAGER SECONDARY
STATISTICS command, code 37, returns statistics for a specific secondary
device.
Network

Each transaction will update the counters until their maximum value is
reached.
to reset the counters before beginning the diagnostic period so that the counts
start

The second command, REPORT NETWORK MANAGER NETWORK
STATISTICS — code 38, returns statistical counters for an specific media
channel.
secondary
not incremented after reaching their maximum value and must be reset
explicitly

The
and statistics on network performance. The statistics are counts for Network
Manager
their

These statistics are counters reflecting the communications between

Manager and the secondary

Then the command must be issued to reset the counters. You may want

at the zero baseline.

The counts reflect the activity between

addresses. Like the secondary statistics counters,

with the special command sequence.

REPORT HIU STATUS command returns the connection status of the HIU

to HIU communications. The counters are not

maximum value and must be explicitly reset.

Statistics

the

.

the Network Manager and all

these counters are

updated after reaching

UNILINK HOST

USER MANUAL

ADAPTER 2–48

CHAPTER

3

CONFIGURING

HOST COMPUTER POR

3.1 THE HOST COMPUTER INTERFACE

The

UNILINK Host
devices through a serial binary data interface using EIA RS–232–C control
signals and EIA RS–423–A drivers as illustrated in Figure 3–1. This port is
configurable for baud rates up to 38.4K bits per second; synchronous or
asynchronous
A

choice of two data link protocols are available;
Protocol (NITP) or BDLC, a byte-oriented subset of the ANSI X3.66 standard
protocol.

Adapter communicates with a wide range of host computer

modem operation; full or half duplex; and even, odd, or no parity

the Non–Intelligent T

Host

UNILINK

RS–232–C/RS–423–A

Computer

THE

T

.

erminal

Figure 3–1 Host Computer Interface

UNILINK HOST

USER MANUAL

ADAPTER3–1

CONFIGURING THE HOST COMPUTER PORT

3.2 RS–232–C/RS–423–A PHYSICAL INTERFACE

Port 3 on the UNILINK Host Adapter, shown in Figure 3–2, is a serial
communications interface which implements a subset of RS–232–C control,
data, and timing signals using RS–423–A drivers and receivers. It is a 25-pin
female
to
Type “D” pin assignments as listed in Table 3–1. Any pins not listed should
remain vacant in order to prevent damage to the host computer or the
UNILINK

“D” connector wired

as Data T

erminal Equipment (DTE) for connection

Data Communications Equipment (DCE). This connector uses the RS–232–C

Host Adapter

.

Port

1

Host

Port

2

Communications Port

Port

3

Figure 3–2 Host Communications Port

Port

AC

4

GND

NEUTACLINE

I/O

1

2 3 4 5

A000654

UNILINK HOST

USER MANUAL

ADAPTER 3–2

CONFIGURING THE HOST COMPUTER PORT

T

able 3–1 RS–232–C/RS–423–A “D” Connector Pin

Assignment

3.2.1

Interchange

Circuit

AA 1 101
AB
BA

BB
CA
CB
CC
CD

CF
DB
DD

Since

the adapter will typically be operating in noisy industrial environments,

it is recommended that the cable length not exceed 50 feet.

Connection to DCE Equipment

Port

3 is configurable for synchronous or asynchronous modem operation, even,

odd,

or no parity

are

configured using the two dipswitch banks shown in Figure 3–3. The actual

settings

are described in more detail in Paragraph 3.3.1.1.

, and baud rates up to 38.4K bits per second. These parameters

Connector

Pin No.

7
2
3
4
5
6

20

8
15
17

CCITT Description

Protective Ground
102
103
104
105
106
107

108/2

109

114
115

Signal Ground

T

ransmitted Data
Recieve Data
Request To Send
Clear To Send
Data Set Ready
Data Terminal Ready
Recieve Line Signal

ransmitter Signal

T
Reciever Signal

Element
Element

Detector

Timing
Timing

Number 1

2

LEDsResetNumber

Figure 3–3 Dipswitch Locations

UNILINK HOST

USER MANUAL

ADAPTER3–3

CONFIGURING THE HOST COMPUTER PORT

When the synchronous modem operation is selected, the adapter expects the
modem to provide the clocking signals on pins 15 (DB) and 17 (DD). Selecting
synchronous modem operation does not mean that you have selected a
synchronous data link protocol such as the bisynchronous data link protocol.
The

adapter supports two asynchronous data link protocols which are described

in

further in Paragraph 3.3.

3.2.2

Connection to DTE Equipment

You can also connect a host computer that has a DTE port, such as a
microcomputer, to Port 3 for asynchronous communications by using a null
modem cable. A null modem cable uses 25-pin type “D” connectors and
RS–232–C cable wired as shown in Figure 3–4. Both the adapter and the
attached host see that each is connected to a DCE device. The attaching cable
should
distributor

not exceed 50 feet in length. Y

(P/N;VPU–200–3605).

Attached

DTR

Device

DTE

1

GND

25

TxD
RxD
RTS
CTS
DSR

GND

DCD
RxCLK–No connection

ou may order

UNILINK Host Adapter

GND

TxD
RxD
RTS
CTS

DSR

GND

DCD

this cable from your Siemens

DTE

1

25

DTR

UNILINK HOST

USER MANUAL

TxCLK–No connection

14

13

13

14

Figure 3–4 Cable For Connecting To DTE Equipment (Null

Modem)

ADAPTER 3–4

I002378

CONFIGURING THE HOST COMPUTER PORT

The

IBM PC/A

modem

cable diagram for the IBM PC/A

Tr uses

a 9-pin “D” connector for its serial interface

T port is shown in Figure 3–5.

IBM PC/AT 9–Pin UNILINK Host Adapter 25–Pin

port. A null

13

1

25

14

RI
CTS
RTS
DSR

9

6

1

DTR
SD

RD
DCD

TxD
RxD

RTS
CTS
DSR

GND
DCD

GND

5

Figure 3–5 IBM PC/AT 9-Pin Null Modem Cable Diagram

UNILINK HOST

USER MANUAL

ADAPTER3–5

CONFIGURING THE HOST COMPUTER PORT

3.2.3 Multidrop

You can multidrop up to 32 adapters using modems in a multipoint circuit as
shown

in Figure 3–6. This allows the
networks; however, each adapter must use the BDLC protocol. Each adapter
must be assigned a unique address with dipswitches. The BDLC protocol uses
the addresses to route messages to the correct network. A multipoint circuit
represents the network layer of the Open Systems Interconnection model
described further in Reference 4 in the Preface and in the TIWAY I Systems
Manual

(PPX:TIW

Host

Computer

4-wire leased line

or equivalent wire

Host Inter

Modem Modem

face Cir

AY–8101).

cuit

host computer to control multiple TIWAY I

Modem

Modem

UNILINK

Host Adapter

UNILINK

Host Adapter

UNILINK

Host Adapter

TIWAY1

Network #1

TIWAY1

Network #2

TIWAY1

Network #3

UNILINK HOST

USER MANUAL

Figure 3–6 Multidrop Host Interface Circuit

You should select half-duplex operation for the
modems

when you

multidrop to prevent the network

modems from simultaneously raising the carrier.

ADAPTER 3–6

NOTE

CONFIGURING THE HOST COMPUTER PORT

3.2.4 XON/XOFF

XON/XOFF flow control is provided at Port 3 to accommodate host computers
with

small input buffers. This is achieved with the XON and XOFF flow
characters sent from the host computer. Transmission will stop within four
characters
characters must be sent as the 8-bit hexadecimal characters 11 and 13,
respectively, with the eighth bit set to zero. For NITP, the XON and XOFF
characters must be sent as 7-bit ASCII characters 11 and 13 with the parity
matching the host computer parity. This flow control will operate with either
the NITP or BDLC protocols, but the adapter must be set for Full Duplex
communications

The adapter will recover from host computer failures by resetting the flow
control
frame

If
host device that implements XON/XOFF flow control with the BDLC protocol,
the
If
device,
as a convenience for the host devices; the adapter will not try to stop a host
transmission

when

will be discarded and must be retransmitted by the host computer

you are using a Network

BDLC data values 1

possible, you should deselect the XON/XOFF flow control on the NIU or host

or select the NITP

Flow Contr

after XOFF is received from the host. For BDLC, the XON and XOFF

by setting Position 3 of Dipswitch 2 up.

the starting delimiter of the next frame is received. However

with XOFF

ol

control

, that

.

Interface Unit (NIU); i.e., Ethernet, Sytek, etc., or a

1 and 13 hex may inadvertently trigger the flow control.

protocol on the adapter

.

. Flow control is only provided

UNILINK HOST

USER MANUAL

ADAPTER3–7

CONFIGURING THE HOST COMPUTER PORT

3.3 HOST PORT COMMUNICATIONS

The UNILINK Host Adapter provides a choice of two data link layer protocols
for ensuring data integrity through the physical link; the Byte–oriented Data
Link Control (BDLC) protocol and the Non–Intelligent Terminal Protocol
(NITP).
checking functions. In addition, the BDLC protocol provides for link
disconnection and sequence control. The protocol and other host port
parameters are selected with dipswitches. Several factors are important in
deciding

Both protocols include link establishment, message

which protocol to use.

framing, and error

3.3.1

Choosing a Host Pr

The NITP protocol was designed to be simple and still provide data integrity.
The

major features of NITP are listed below

 It

works in a point-to-point circuit, connecting the host computer to the
adapter.
have

the ability to address individual adapters.

 Messages are transmitted in a frame that includes beginning and

ending

otocol

.

NITP

cannot be used in a multipoint circuit because it does not

delimiters, message character count, and a checksum.

:

Character

Count

Message

Body

ECC

;

Figure 3–7 NITP Message Structure

UNILINK HOST

USER MANUAL

ADAPTER 3–8

CONFIGURING THE HOST COMPUTER PORT

 The

 It is designed to work with a wide range of ASCII host devices, from

 It

 It is easier to implement than the BDLC protocol, but it is also much

More detailed specifications are given in Appendix A.

host computer must wait for the adapter response
issued, before another command can be
sequence,
the

ASCII

supports a subset of the ASCII character set,
The
semicolon delimiter and the next beginning colon delimiter
computer

slower
bytes

illustrated in Figure 3–8,

command.

terminals to intelligent workstations.

adapter

for each data value. For example, the hexadecimal value:

will ignore all other ASCII characters between the ending

can use these characters for routing control.

since the data is transmitted as ASCII characters requiring two

0E hex



/ \ becomes

30

45 (ASCII characters “0” and “E”)

issued. This command/response

ensures that the response matches

“:”, “;”, “0–9”, and “A–F”.

for the command

, so the host

Host

Computer

UNILINK

Host

Adapter

NITP Host
Command

Network
Response

Figure 3–8 NITP Command/Response Sequence

UNILINK HOST

USER MANUAL

ADAPTER3–9

CONFIGURING THE HOST COMPUTER PORT

The BDLC protocol is a byte–oriented subset of the ANSI X3.66 standard
protocol,
BDLC

similar to the ISO standard

protocol are listed below

 It provides a higher level of data integrity and throughput

improvements

 It uses send and receive counts in a control field for improved data

integrity.

 Throughput is improved by transmitting the data as eight-bit binary

values or hexadecimal, making this protocol approximately twice as
fast as NITP. However, you will have to write and/or install the BDLC
protocol

over NITP

driver software on your host computer

HDLC protocol. The major features of the

.

, but it is also more complex to implement.

.

 Additional

outstanding transaction capability, illustrated in Figure 3–9. This
allows the host computer applications software to continue issuing
commands
can issue a network request to secondary device #1, then another to
secondary
from

 It uses an address to distinguish individual adapters in a multipoint

host

More detailed specifications are given in Appendix B.

throughput improvements are gained by using the multiple

before the network response is returned. The host computer

device #2, followed by the command to retrieve the

secondary device #1.

interface circuit as described in Paragraph 3.2.3.

response

UNILINK HOST

USER MANUAL

ADAPTER 3–10

CONFIGURING THE HOST COMPUTER PORT

Host

Computer

UNILINK

Host

Adapter

BDLC Host Command

RR, “Message Received”

BDLC Host Command

RR, “Message Received”

RR, “Poll”

First Network Response

RR, “Poll”

Second Network Response

Figure 3–9 BDLC Multiple Outstanding Transactions

Another consideration is that of the six configurable modes described in
Chapter 2, two of those modes emulate the original TIWAY I Host Adapter,
meaning that they require the NITP protocol. If you plan to use either the
Master
you must also use the NITP protocol because these modes do not support
commands for configuring network parameters and the dipswitch used to
define

Host Interface Unit (MHIU) or Host Interface Unit (HIU) in EHA mode,

the BDLC address is used to define those network parameters.

Another factor to consider is the type of secondary devices that will be on your
network. If you will be connecting Computer Interface Modules (CIM) or
Intelligent Tank Transmitters (ITT) in CIM mode, you must configure the
adapter
used

as an MHIU/EHA

in the TIWAY mode without the above restriction.

which requires the NITP protocol. ITT

s may also be

UNILINK HOST

USER MANUAL

ADAPTER3–11

CONFIGURING THE HOST COMPUTER PORT

     

The host port communication parameters are configured with two 10-position
dipswitches
NITP as the operating protocol, set position 1 of Dipswitch 1 up as shown in
Figure

located at the front of

3–10.

the adapter as shown in Figure 3–3. T

o select

DIPSWITCH 1

12345678910

U
P

UP=NTP

DIPSWITCH 2

1

2345678910

U
P

MSB LSB

UP = SYNCHRONOUS
DOWN = ASYNCHRONOUS

UP = FULL DUPLEX
DOWN = HALF DUPLEX

KEY

UP DOWN

HOST COMMAND

TIMEOUT

UP = TEST MODE
DOWN = RUN MODE

UP = HIU/EHA &

DOWN = MHIU/EHA

HOST PORT BAUD RATE

IO LOOP TEST

HOST PORT

HOST PORT

UNILINK HOST

USER MANUAL

UP = EVEN PARITY
DOWN = ODD PARITY

UP = PARITY ENABLED
DOWN = PARITY DISABLED

Figure 3–10 NITP Dipswitch Settings

The host port parameters specify the physical layer
protocol parameters and do not imply that the data
link protocols can be either asynchronous or
synchronous.

Both the BDLC and NITP protocols are

asynchronous data link layer protocols.

ADAPTER 3–12

HOST PORT

HOST PORT

NOTE

CONFIGURING THE HOST COMPUTER PORT

Next set the positions on Dipswitch 2 to correspond with the communication
parameters set for the host computer. The adapter
the

host computer using seven data bits, one start bit, and

rate

settings for Positions 5–8 of Dipswitch 2 are shown in T

Position 1 of Dipswitch 2 enables or disables parity bit generation and
checking.

Position 2 of Dipswitch 2 selects even or odd parity when parity
generation

Position 3 of Dipswitch 2 selects full duplex or half duplex operation.

and checking is enabled.

always communicates with

one stop bit. The baud

able 3–2.

Position
communications.
the TxCLK (DD) and RxCLK (DB) RS–232–C control signals. The
adapter will not process synchronous control characters from
synchronous

4 of Dipswitch 2 selects synchronous or asynchronous modem

Selecting synchronous only enables the

data link protocols such as BiSync.

adapter to use

Table 3–2 Host Port Baud Rates

Dipswitch 2

Switches

MSB LSB

5678

100

0

1

0

0

1

0

1

0

0

1

0

1

0

1

0

1

1

1

1

1

1

1

0

1

1

0

0

0

1

1

0

1

1

0

0

0

1

0 = Down
1=Up

Baud Rate

110
150
300
600

1200
2400
4800

9600
19200
38400

UNILINK HOST

USER MANUAL

ADAPTER3–13

CONFIGURING THE HOST COMPUTER PORT

U
P

DIPSWITCH 1

1

2345678910

MSB LSB

Position
be

9 on Dipswitch 2 is for selecting the adapter’s operational mode and will

discussed in more detail in Chapter 2. Position 10 should be down for normal
operation. The other switch positions on Dipswitch 1 define the TIWAY I
network

To

parameters and are discussed in more detail in Chapter 4.

select the BDLC protocol as the operating protocol, set position 1 of Dipswitch
1 down as shown in Figure 3–11. With BDLC, the host port parameters are
configured with both dipswitches. Since the data is transferred as 8-bit bytes,
there

is no parity bit selection.

DIPSWITCH 2

1

2345678910

U
P

MSB LSB

UP = SYNCHRONOUS
DOWN = ASYNCHRONOUS

UP = FULL DUPLEX
DOWN = HALF DUPLEX

UNUSED

UP = TEST MODE
DOWN = RUN MODE

UP = HIU/EHA &

DOWN = MHIU/EHA

HOST PORT BAUD RATE

IO LOOP TEST

HOST PORT

HOST PORT

UP DOWN

HOST COMMAND

TIMEOUT
00 = STANDALONE

NM MODE
01 = 10 SEC.
10 = 20 SEC.
11 = 40 SEC.

BDLC ADDRESS

UNUSED

UNUSED

DOWN = BDLC

PROTOCOL

KEY

UNUSED

Figure 3–11 BDLC Protocol Dipswitch Settings

UNILINK HOST

USER MANUAL

ADAPTER 3–14

CONFIGURING THE HOST COMPUTER PORT

T

able 3–3 BDLC Protocol Address

Dipswitch 1

Address

45678

Positions

10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

0
1
2
3
4
5
6
7
8
9

00000
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

0

0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1

0

0

1

0

1

1

0

1

0

1

1

1

1

0

0

0

0

0

1

0

1

1

0

1

0

1

1

1

1

0

0

0

0

0

1

0

1

1

0

1

0

1

1

1

1

0

0

0

0

0

1

0

1

1

0

1

0

1

1

1

1

1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1

0 = Down

Set

the adapter’s BDLC protocol address using T
positions on Dipswitch 2 to correspond with the communication parameters of
the

host computer
Dipswitch 2 defines the adapter’s operational mode (discussed further in
Chapter
Dipswitch 1 define the Host Command timeout value discussed in Paragraph

3.4.

2). Position 10 should be down for normal operation. Positions 9–10 of

. The baud rate settings are shown in T

1 = Up

able 3–3 as a guide

able 3–2. Position 9 of

UNILINK HOST

and set the

ADAPTER3–15

USER MANUAL

CONFIGURING THE HOST COMPUTER PORT

3.4 HOST COMMAND TIMEOUT

The

Host Command T
a response from the adapter will be returned within that limit. If the adapter
has not received a response from the secondary device before this time period
expires,
This
time-out

Note
any host commands since the timeout occurs immediately. When the Host
Command Timeout is set to 0, the adapter is configured in the Standalone
Network

the adapter will return the ERROR RESPONSE to the host computer

time-out

that a timeout value of 0 seconds signifies that the adapter will not accept

function operates with either host communication protocol for the

values shown in T

Manager (SANM) mode.

The adapter must be reset before any dipswitch
changes are recognized.

imeout is the user

able 3–4.

NOTE

-selectable time

period that guarantees

.

Table 3–4 Host Command Timeout Dipswitch Settings

DIPSWITCH 1

Position

9

Down

Down
Up
Up

10

Down

Up
Down
Up

Description

0 sec

–

Accepts No

Host Commands

(SANM Mode)
10 sec
20 sec
40 sec

Timeout
Timeout
Timeout

UNILINK HOST

USER MANUAL

ADAPTER 3–16

CHAPTER

4

THE

TIWAY I NETWORK POR

4.1 NETWORK PORTS

The UNILINK Adapter offers a choice of two physical interfaces for network
communications;
the model numbers and the type of interfaces in each.

the Local Line

or Modem interfaces. The following table lists

Table 4–1 UNILINK Adapter Models

Model Number
PPX:500–7111

PPX:500–7112
PPX:500–7113
PPX:500–7114

More information on the media types can be found in the TIWAY I Systems
Manual (PPX:TIWAY–8101) and in the UNILINK Adapter Installation and
Operation

Manual (PPX:TIW

Network Port
Dual Local Line

Dual RS–232–C/423
Dual Local Line
Dual RS–232–C/423

AY–8106).

Supply V
120 V

AC

120 V

AC

240 V

AC

240 V

AC

oltage

TS

UNILINK HOST

USER MANUAL

ADAPTER4–1

THE TIWAY I NETWORK PORTS

4.1.1

Local Line Inter

face

Port 1Port 2 Port 3 Port 4

I/O

12345

Local Line Interface Ports

Figure 4–1 Local Line Interface Ports

The Local Line interface to TIWAY I is a female 9-pin “D” connector shown as
Ports

1 and 2 in Figure 4–1. Port 1 is the primary network port.
support for redundant media transmission when Ports 1
a redundant twisted pair cable network (discussed further in Paragraph 4.2 ).
The

pin assignments for these ports are given in T

and 2 are connected to

able 4–2.

Port 2 provides

Table 4–2 Local Line Connector Pin Assignments

Pin

Name

1
2

3

Sheild
4
5
6

LLM+
7
8
9

LLM–

Description

Reserved
Reserved

Cable shield and signal common
Reserved
Reserved
Positive biased signal line
Reserved
Reserved
Negative biased signal line

UNILINK HOST ADAPTER 4-2

USER MANUAL

THE TIWAY I NETWORK PORTS

The

TIWAY I Local Line interface has the advantage of being more economical

than

the modem interface since
Belden 9860 or Belden 9271. Figure 4–2 shows the
the

network trunkline cable, which can generally extend up to 25,000 feet
droplines
cable

up to 100 feet in length. Figure 4–3 is a chart showing the

distances compared to the number of stations on the TIWAY I network.

PM550 CIM users should refer to Appendix C for
different media length factors.

Host

Computer

the media is shielded twisted pair cable, such as

TIWAY I bus structure with

maximum

NOTE

RS–232–C/RS–423–A
Host Interface Cable

with

UNILINK

UniLink Host Adapter ( MHU)

Figure 4–2 TIWAY I Bus Structure

TIWAY

I

UNILINK HOST

USER MANUAL

ADAPTER4–3

THE TIWAY I NETWORK PORTS

30
25
20

15
10

8
7
6
5
4

3

Cable Distance (1000’s of feet)

2

1

19.2

k bps

38.4 k bps

57.6 k bps

1

15.2 k bps

1

15.2 k bps or lower

Cable

10 50 100 250

205

Unit Loading (Number of Stations)

Figure 4–3 Number of Local Line Secondaries vs.

Cable Distance

Belden 9860

Belden 9271

I003648

Signals are coupled between the transmission line and the transmit/receive
circuits to provide a level of rejection to normal AC power frequency
interference
twisted
600,

1200, 2400, 4800, 9600, 19.2K, 38.4K, 57.6K, and 1
half-duplex mode and NRZI encoding. The Local
synchronous

and other noise sources. Information is transferred on the TIWAY I

pair media asynchronously at user selectable data rates of 110, 150, 300,

15.2K bits per second, in

Line interface does not support

operation or NRZ.

UNILINK HOST ADAPTER 4-4

USER MANUAL

THE TIWAY I NETWORK PORTS

4.1.2

Modem Inter

face

Port

Interface

1

Ports

Port

2

Port

3

Port

AC

4

GND

NEUTACLINE

1

2 3 4 5

Figure 4–4 RS–232–C/RS–423–A Modem Interface Ports

The

modem interface

EIA

RS–232–C standard that uses EIA RS–423–A drivers. This interface uses a

female

25-pin “D” type connector on both Ports 1 and 2
These two ports support redundant media transmission when connected to
redundant modem networks. The pin assignments shown in Table 4–3 are
supported.
caused

All other pins should be left vacant to prevent damage which may be

by non-standard pin usage.

is a standard “T

ype E” DTE configuration as defined in the

as shown in Figure 4–4.

I/O

A000654

UNILINK HOST

USER MANUAL

ADAPTER4–5

THE TIWAY I NETWORK PORTS

Table

The line drivers and receivers meet the requirements for the RS–423–A and
RS–232–C standards. The modem interface is user–selected for either
asynchronous or synchronous operation at data rates of 110, 150, 300, 600,
1200,

Modem interface circuits can be longer than the 25,000 feet limit of the Local
Line interface. This interface must be used for cross-building or cross-town
circuits.
Non-intelligent refers to the class of modems that do not have an internal
command
have
meet
modems
data
necessary because TIWAY I uses the bit-oriented HDLC protocol to transfer
information
provide

4–3

Interchange

2400, 4800, 9600, 19.2K, 38.4K, 57.6K, and 1

The modems used must be non-intelligent and

an

internal command set and should not be used. Generally

the Bell 103, 202, and 208 specifications will work, but the Bell 212A class

will not. In addition to being non-intelligent, the modems must support

transparency which means no start bits, no stop bits,

data transparency

RS–232–C/RS–423–A “D” Connector Pin Assignment

Circuit

AA 1 101
AB
BA

BB
CA
CB
CC
CD

CF
DB
DD

set. Modems such as the Hayes Smartmodemand

between devices.

Connector

Pin No.

7
2
3
4
5
6

20

8
15
17

Most short haul modems are non–intelligent and

.

CCITT Description

102
103
104
105
106
107

108/2

109

114
115

Protective Ground
Signal Ground
T

ransmitted Data
Receive Data
Request To Send
Clear To Send
Data Set Ready
Data Terminal Ready
Recieve Line Signal

Detector

T

ransmitter Signal

Element

Reciever Signal

Element

15.2K bits per second.

have data transparency

and no parity

Timing
Timing

compatibles

, modems that

do

. This is

.

UNILINK HOST ADAPTER 4-6

USER MANUAL

THE TIWAY I NETWORK PORTS

You also have a choice of using either NRZ or NRZI encoding with the modem
interface.

A special Clear-to-send (CTS) to transmit timing delay has been provided for
use
There is also an RTS/CTS timeout. These delay values are set through
configuration

NRZI is recommended because of its self-clocking properties.

with radio link modems, ranging from 0 ms to 1,000

commands described in Chapter 2 and Chapter 5.

ms in 10 ms increments.

4.1.3

Runaway T

The UNILINK Host Adapter is equipped with a timeout or runaway
transmitter recovery mechanism which ensures that the transmitter does not
remain turned on longer than twice the time required to send the maximum
length
a

hardware reset, discarding all macro buffers and any outstanding directives.

ransmitter Recovery

message. If the transmission exceeds this limit, the adapter will

perform

NOTE

The hardware reset restores the adapter to the
initialized or power-up state. At this point, the
adapter

will have to be reconfigured and the network

restored to its operating state.

UNILINK HOST

USER MANUAL

ADAPTER4–7

THE TIWAY I NETWORK PORTS

4.2 REDUNDANT MEDIA TRANSMISSION

Most TIWAY I conformant devices support a redundant media scheme which
provides
Should access to a device fail on one channel, communications can be
automatically or manually switched to the alternate channel. This type of a
circuit is illustrated in Figure 4–5. Examples of the software commands are
given

active access to a device over one of two independent media

in Chapter 2.

channels.

UNILINK

Bus

(main trunk)

Drop

Cables

Secondary Bus
(alternate trunk)

Up to 254
Secondaries

Figure 4–5 Redundant Media Circuit

NOTE

Redundant
mission reliability. However

media is

provided to improve a network’

, the adapter cannot use
the dual media ports to access two independent
networks.

s

UNILINK HOST ADAPTER 4-8

USER MANUAL

THE TIWAY I NETWORK PORTS

4.3 TIWAY I HDLC NETWORK PROTOCOL

The TIWAY I network uses the HDLC protocol in the unbalanced, normal
response mode (UNRM) for transmission of commands and responses. In this
mode a single Network Manager (primary) controls the flow of messages
between secondary devices. Information flows between the primary and
secondaries inside HDLC I-Frames or information frames. The destination of
the

frame is specified by the address field, the nature of the frame by the
field, and any data specified by the information field. The TIWAY I primitive
requests and responses are encapsulated inside HDLC I-Frames according to
the

format shown in Figure 4–6.

Flag Address Control Information FCS Flag

Figure 4–6 HDLC Frame

control

UNILINK HOST

USER MANUAL

ADAPTER4–9

THE TIWAY I NETWORK PORTS

4.4 SETTING THE NETWORK PORTS PARAMETERS

The

network ports must be explicitly enabled with the CONFIGURE HIU and
CONFIGURE NETWORK MANAGER commands. The syntax for these
commands
these

The choice of the host port protocol also determines whether network port
parameters can be defined on the dipswitches or through internal constants.
The BDLC protocol uses both dipswitches to define the host port parameters
and

will use these internal constants for network defaults:

D

is given in Chapter 5. The network parameters specified explicitly in

commands overrides the default values set by the dipswitches.

Local Line media —
d 1

15.2K baud,

d

half duplex,

d

asynchronous, and

d NRZI

D

RS–232–C/RS–423–A media —

d

9600 baud,

d

full duplex,

d

synchronous, and

d NRZ

The NITP protocol uses the values defined on Dipswitch 1 as the defaults as
shown

in Figure 4–7. The network parameters are then set with Positions 2–8 of
Dipswitch
given in Table 4–4. These settings should match the settings for any other
T IWAY

1 as illustrated in Figure 4–7. The applicable baud rate settings are

I network devices.

UNILINK HOST ADAPTER 4-10

USER MANUAL

THE TIWAY I NETWORK PORTS

DIPSWITCH 1

1

2345678910

U
P

MSB LSB

UP = SYNCHRONOUS
DOWN = ASYNCHRONOUS

UP = FULL DUPLEX
DOWN = HALF DUPLEX

UP = NRZI
DOWN = NRZ

UP = NITP

HOST COMMAND

TIMEOUT

TIWAY I BAUD RATE

TIWAY I

TIWAY I

TIWAY I

Figure 4–7 Network Port Dipswitch Settings

NOTE

The Local Line interface will always be
asynchronous, half duplex, and use NRZI encoding
regardless of the setting of these dipswitches.

Table 4–4 Network Port Baud Rates

MSB LSB

5678
0

100
1

0

0
0
0
1
1
1
1
1
1
111

1
1
0
0
0
0
1
1

1

1

1

0

1

1

0

0

0

1

1

0

1

1

0

0

0

1

1

0

1

1

01= Down

= Up

Network

Baud Rate

110
150
300
600

1200
2400
4800

9600
19200
38400
57600

115200

UNILINK HOST

ADAPTER4–11

USER MANUAL

CHAPTER

5

HOST

COMMAND SET REFERENCE

5.1 INTRODUCTION

This chapter presents the syntax for each command. The command syntax

5.1.1

descriptions
at 00 to FE hexadecimal). The command syntax conventions are defined in
Paragraph 5.1.1. Certain network address values have special meanings and
are

described in Paragraph 5.1.3.

Paragraph 5.8 provides a summary of the command syntax including both the
command and response syntax. Paragraph 5.9 provides a list of the command
codes

and descriptions, listed in numerical order and Paragraph

similar

Command Syntax Conventions

begin in Paragraph 5.2 and are listed in numerical order (starting

list that groups the commands according to their use.

Command

Code

Parameter#1Parameter

#2

5.10 provides a

Parameter

#n

Figure 5–1 Command String Structure

Command strings contain the one-byte command code and may include one or
more parameters as defined by each command’s syntax. All values in the
command string are in hexadecimal notation. The selected host interface
protocol,
transferred in binary format or converted to ASCII characters. The following
conventions are used to define the command syntax used in the succeeding
sections:

discussed in Chapter 3, will determine whether the command string is

D The most significant bit, labeled Bit 0, is the left most bit in the byte,

word,

or long word.

D All command code numbers are one byte, hexadecimal values and will

always

D Each letter in a command parameter indicates a nibble (four bits) so

that

d

d

d

be the first byte in the command string.

a:
byte is represented as aa
word is represented as aaaa
and a long word is represented as aaaaaaaa

D Parameters containing more than eight nibbles (long word) are

represented

as aaaa...

UNILINK HOST

USER MANUAL

ADAPTER5–1

HOST COMMAND SET REFERENCE

D

All codes and parameters are separated by spaces.

D

Optional parameters are surrounded by parentheses, like (aa bb).

D Parameter sequences that may be repeated are surrounded by

brackets,

like [aa bb].

D Certain

command

d

d

d

d oo — the option code. Commands may have one or more option

d pppp...

letters designate a specific parameter type

syntax descriptions for easier identification. These are:
aa — the secondary device address.
ss — the Source Identification number
rr — the reset counters code.

codes.

— a TIWAY I Primitive.

.

used throughout the

UNILINK HOST

USER MANUAL

ADAPTER 5–2

HOST COMMAND SET REFERENCE

5.1.2

Usage Description

A usage description is included with each command reference to give an
indication of when the command should be used. The meaning of the usage
descriptors

CONFIGURATION

INITIATION

OPERATION

PERFORMANCE

TERMINATION

are

This command is used to configure the adapter
for operation. This command can only be issued
once to each adapter after they have been reset
or powered up.

This command is used to initialize the network
devices.

This command is used for ongoing
communications between the host computer
and the network devices.

This command is used to gather statistical
performance or status information on the
adapter and the network devices, and to
redefine certain operating parameters to
improve network performance.

This command is used to shut down or
terminate network devices.

UNILINK HOST

USER MANUAL

ADAPTER5–3

HOST COMMAND SET REFERENCE

The cycle at power

Figure 5–2 Command Usage Cycle

-up or reset is shown in Figure 5–2.

Configuration

Initiation

Operation

Performance

Termination

5.1.3 Secondary

Secondary addresses are one byte in length and range from 1 to 254. The
addresses
Normally the address 255 is used as a shorthand method to indicate that the
command should be processed for all secondary devices on the network. Care
must

be

used with this shorthand method because a host command timeout may

occur

before the response has been gathered from all of the secondaries.

Your network will operate more efficiently if you number your secondary
devices
remaining

and HIUs beginning with address

Addr

esses

0 and 255 are reserved for special functions as indicated in T

“1” and consecutively numbering the

devices.

able

5–1.

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Table 5–1 Secondary Addresses

5.1.4 Active

Figure 5–3 is a decision tree illustrating the command codes that are active in
each configurable mode. In addition to mode, the command tree asks whether
the

major components have been configured with their associated configuration

commands.

Intended
Mode

MHIU
EHA

Decimal
Address

0

1–254

255

Hexadecimal

Address

00

01–FE

FF

Command Codes In Each Mode

Adapter
Configured
(Command 20)

YES

NO

HIU Configured
(Command 1
and Initialized by
Network Manager

1)

Usage

Reserved for special functions,
refer to individual commands.

A

vailable for secondary device

addresses.
Reserved for special functions,

normally used to indicate all
secondary devices are to be
ef

fected by the command.

Active

Network

Manager
Configured
(Command 30)

1–8, 21, FC–FF
1–8, 20–21. FC–FF

Command
Codes

Power

up

HIU
EHA

NM

MHIU

HIU

YES

NO

YES

NO

YES

NO

YES

NO

YES

NO

YES

NO

YES

NO

YES

NO

YES

NO

Figure 5–3 Active Command Tree

1, 2, 4–8, 21,FC–FF
20, 21,FC–FF

21, 31–38, FC–FF
21, 30–32, 34–38, FC–FF

20, 21 FC–FF
1–2, 4–10, 12–1C, 21, 30–32, 31–38, FC–FF
6–8, 10–1C, 21, 30–32, 34–38, FC–FF

6–8, 10–1C, 21, 31–38, FC–FF
6–8, 10–1C, 21, 30–32, 34–38, FC–FF

1–2, 4–10, 12–1C, 21, FC–FF
6–8, 10–1C, 21, FC–FF

20, 21, FC–FF

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5.2 ERROR RESPONSE

An ERROR RESPONSE, rather than the normal command response, will be
returned

when the host request is invalid.

Response: 00

Parameters:

dddd Error codes. All error codes and corrective actions are given in

aa The secondary address associated with the error code. This

dddd (aa)

Chapter

parameter

6.

is only included if applicable.

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5.3 BASE HIU COMMANDS

The

Base HIU commands are backward

for

the TIWAY I Host Adapter
to be issued to connect and disconnect secondaries, send data to and from
secondaries, and read secondary statistics. Your applications software must
wait for a response to be returned before issuing another command if you are
using

the NITP protocol. If you are using the BDLC protocol, you can have up to
two outstanding transactions before the adapter will return the Receiver Not
Ready

(RNR) BDLC control frame. These commands are listed below



Send Network Data — 01



Broadcast Network Data — 02



Poll Secondary — 03 (Available only in MHIU/EHA mode)



Connect Secondaries — 04



Disconnect Secondaries — 05



Read Secondary Log — 06

. These commands cause a direct network request

compatible with the original commands

.



Read Secondary Diagnostics — 07



Read Adapter Diagnostics — 08

These commands will not be accepted by either the hosted or the stand-alone
Network

Manager modes.

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5.3.1

Send Network Data — 01

The SEND NETWORK DATA command sends a specified host Primitive to a
network secondary via the Network Manager. Once the Primitive has been
received by the secondary, the Network Manager polls the secondary for the
Primitive response and returns it to the issuing HIU. The HIU then forwards
the

Primitive response to the attached host computer

Command:

Response:

Usage: OPERATION

Modes:

Parameters:

aa
pppp The TIWAY I Primitive data (command or response). This

01 aa pppp...

01 aa pppp...

MHIU/EHA, HIU/EHA, MHIU, HIU

The secondary address to receive the Primitive data.

parameter

begins with the length field of the Primitive.

.

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5.3.2 Br

The BROADCAST NETWORK DATA TRANSFER command sends the
Primitive data to all online secondary devices. The secondary device log
contains
this
checks

If the adapter is configured as an MHIU in EHA mode, the host applications
software must issue a POLL command for each secondary device to collect the
responses
include a data element that is set in the secondary with the broadcast and
checked by the host applications software by sending a SEND NETWORK
DATA
element can also be checked by the secondary devices program to cause it to
perform a programmed process. This function can be more efficiently handled
in

oadcast Network Data T

only those secondary devices in the network that are online. However

type of

non-MHIU/EHA networks by using macros for data acquisition.

information transfer does not use the full TIWAY I HDLC integrity

to ensure message delivery

or some responses may be lost. In any other configuration, you should

command to determine if the broadcast message was received. The

ransfer — 02

.

NOTE

Before the data is broadcast, all pending TIWAY I
I–Frames from all HIUs will be processed. Then no
further directives will be processed until the
broadcast completes. This could have a serious
impact on the response time for normal network
operations and should be used carefully.

,

data

The

following are typical uses for this command.
 Time synchronization for all secondary devices. This could be used to

signal all secondaries to reset their counters at the beginning of a
production

 Data collection via a snapshot read. The broadcast could signal the

secondaries to move data to a designated area in the secondary device
which
command.

period.

will be retrieved later with a POLL or SEND NETWORK DA

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CAUTION

You should not issue the BROADCAST
NETWORK
network contains Intelligent Tank
Transmitters (ITTs) as secondary devices, or
you could lose responses. Also, sending a
BROADCAST NETWORK DATA TRANSFER
command when your adapter is configured as
either

an MHIU or an HIU will cause a network
HDLC error to be logged even though the
information was received. This error will be
included in the statistics from the READ
SECONDARY DIAGNOSTICS, REPORT HIU
STATUS, REPORT NETWORK MANAGER
SECONDARY STATISTICS and the REPORT
NETWORK MANAGER NETWORK
STATISTICS commands.

DATA TRANSFER command if

your

Command: 02

Response: 02

Usage: OPERATION

Modes:

Parameters:

MHIU/EHA,

pppp

pppp...

The TIWAY I Primitive request. This parameter begins with the
length field of the Primitive.

HIU/EHA, MHIU, HIU

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5.3.3

Poll Secondary — 03

The POLL SECONDARY command is issued to collect the responses to the
broadcast
the Network Manager (NM). This command is only valid for an adapter
configured

Command: 03

Response: 03

Usage: OPERATION

Modes:

Parameters:

command or a SEND NETWORK DATA command that timed out

as an MHIU in EHA mode.

aa

aa pppp...

MHIU/EHA

aa The
pppp The TIWAY I Primitive data response. This parameter begins

secondary address being polled.

with

the length field of the Primitive.

in

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5.3.4

Connect Secondaries — 04

The CONNECT SECONDARIES command logically connects one or more
secondaries to the network. Each host computer must issue this command for
the

secondary devices that it will be communicating with.

Trying

to connect many secondary devices at the same time could cause the host
command time-out to expire if the secondary devices do not respond in that time
limit.

If this occurs, the error response will be returned and the host computer
will have to retrieve the secondary log to determine which secondary devices
were

connected.

Command: 04 [aa]

Response: 04 [bb]

Usage: INITIATION

Modes:

Parameters:

MHIU/EHA,

aa The

will

HIU/EHA, MHIU, HIU

secondary addresses to be connected. Specifying

attempt to connect all secondaries.

address FF

bb The

none

secondary addresses that

of the secondaries addressed were connected.

connected properly

. If bb is 00 hex,

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5.3.5

Disconnect Secondaries — 05

The DISCONNECT SECONDARIES command removes the specified
secondaries from the secondary log and automatically disables associated
macros,
processing
when it was initialized, then this command also issues a DISC directive that
logically disconnects (possibly causing the secondary device to perform a
hardware reset) the specified secondary from the network. This does not
prevent another HIU or the background monitor from reconnecting the
secondary. Once a secondary device is logically disconnected, it will appear
offline
the

Trying
address FF hex, could cause the host command timeout to expire if the
secondary
RESPONSE
secondary

Command: 05 [aa]

Response: 05 [bb]

setting their MRSWs to the appropriate T

this

command was given permission to issue a DISC on the network

to all HIUs on

exception flag and MRSWs for any macros associated with that secondary

to disconnect many secondary devices at the same time, using the global

devices cannot respond in that time limit.

will be returned

log to determine which secondary devices were disconnected.

the network, causing the remaining network HIUs to set

and your applications software should retrieve the

ermination Code. If the HIU

If this occurs, the ERROR

.

Usage: TERMINATION

Modes:

Parameters:

MHIU/EHA,

aa The secondary addresses to be disconnected. Specifying address

FF will attempt to disconnect all secondary devices listed in the
secondary

bb The secondary addresses that disconnected properly. If bb is 00

hex,

HIU/EHA, MHIU, HIU

log.

none of the secondaries addressed were disconnected.

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5.3.6

Read Secondary Log — 06

The READ SECONDARY LOG command returns the list of secondaries that
are

logically connected to the HIU.

Command: 06

Response:

Usage: OPERATION

Modes:

Parameters:

aa The secondary addresses currently connected to the HIU. If no

06 [aa]

MHIU/EHA,

secondaries

HIU/EHA, MHIU, HIU

are connected, the value returned will be 00.

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5.3.7

Read Secondary Diagnostics — 07

The READ SECONDARY DIAGNOSTICS command returns statistics for the
specified secondary device. Only counts related to the issuing HIU are
returned. With the exception of the number of I–Frames transmitted to and
from the secondary, these counters do not represent an exact count of events
and

are intended only to show trends that may indicate problems. The
will not be updated for offline secondaries or after reaching their maximum
value

of FFFF

this

command with the reset counter code.

Command: 07

Response: 07

Usage: PERFORMANCE

Modes:

Parameters:

aa The

. The host computer must explicitly reset the counters by issuing

aa (rr)

aa (bbbb cccc dddd eeee ffff gggg hhhh iiii)

MHIU/EHA,

reset code parameter is set to 01, the statistics counters for all
secondaries will be reset. The special address cannot be used to
return

HIU/EHA, MHIU, HIU

secondary address. If the special address FF is used and the

the statistics counters for all secondaries simultaneously

counters

.

rr The reset statistics counters code. This optional parameter was

added to the original TIWAY I Host Adapter command to allow
the

counters to be reset.

00 = Return the statistics counters for the specified secondary,
but

do not reset the counters.

01

= Reset the statistics counters for the specified secondary and
do not return any counts. Only the address field
the

command code when this option is selected.
bbbb
cccc The number of TIWAY I HDLC I–Frames successfully

dddd The number of network errors including CRC errors, timeouts,

eeee
ffff
gggg The number of TIWAY I HDLC errors, including command

The number of polls successfully transmitted to the secondary

transmitted

aborts,
The number of TIWAY I HDLC I–Frames received.
This value will always be zero.

rejects (FRMR), invalid HDLC responses, and sequence errors.
This number may reflect errors logged because a BROADCAST
NETWORK DATA TRANSFER command was issued in a
network that contains Intelligent Tank Transmitters (ITTs) as
secondary devices. These errors are logged because the ITT
returned

to the secondary

and the loss of RS–232–C/RS–423–A control signals.

a REJ even though the information was received.

.

is returned with

.

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