Cal Controls 3300, 9300, 9400, 9500P Application guide

Application guide for using communications option for

CAL 3300 / 9300 / 9400 / 9500P controllers - Doc: 33010 / 06 / 0106

Introduction

The 3300 / 9300/ 9400 / 9500P series controllers can all be ordered
or retrofitted with either an RS232 or RS485 serial communications
board. If the controller has the communication board fitted then skip
to the section titled Installation/cabling.

Feature RS232 RS485

Type of transmission lines Unbalanced Differential

Maximum number of drivers 1 128

Maximum number of receivers 1 128

Maximum cable length 15m 1200m

Maximum data rate 19.2Kb/sec 19.2Kb/sec

Maximum CMV +/- 25V +12 to –7V

The table lists the features of both RS232 and RS485 standards.

Cable: To ensure data integrity over long transmission distances, it is
recommended that good quality RS485 cable is used.
Recommended: RS485 - Belden 9841, RS232 - Belden 9501.
Available from leading cable distributors, and stocked by CAL.

Fitting a communications interface board

The RS232 and RS485 interface boards are interchangeable and are
fitted in exactly the same way, please read the fitting and safety
instructions before proceeding.

Caution: Live circuits can hold charge for short periods
after isolation from voltage supply.

Electrostatic precautions should be observed when
handling the controller out of its sleeve.

After isolating the controller from its supply, the controller front bezel
and circuit board assembly can be unplugged from the sleeve. Grasp
the bezel firmly by the recess on each side and pull. A screwdriver can
be used as a lever if required.

To fit the RS232 or RS485 interface you will require the following
parts, which are supplied with the interface.

Nylon full nut
Code: 082-042

Brass half nut
Code: 082-041

Nylon screw
Code: 082-028

Nylon spacer
Code: 082-012

Plug the 5-way female connector on
the comms board into the 5-way
male connector on the controller
board ensuring that the connectors
are all in alignment. At the same time
ensure the hole in the comms board
fits over the screw thread

Screw the half nut onto the comms
board. Do not overtighten but ensure
that it’s tight enough to stop the
board from moving

Cut the top of the screw thread so
that it is level with the top of the
brass nut

Now you are ready to refit the controller into its case. To do this carefully slide
the PCB into the case aligning it with the connector arms at the rear. Then press
the bezel assembly firmly into the sleeve until the latch clicks in order to
compress the gasket and seal to NEMA4 / IP66

Installation / Cabling

RS232 Connections
RS232 has been widely used for interfacing peripherals to PC’s and is
designed for serial communications with a single instrument up to
distances of 15m, in a low electrical noise environment.
Connection is via a screened two-cored cable where the voltage
signal on each line is referenced to the screen which is grounded. .
Most PCs have one or two RS232 compatible ports fitted as standard.
If no RS232 ports are available, an RS232-USB converter cable may be
required.

Controller rear terminal

RS485 Connections
RS485 is half duplex serial communications link and is the standard
most commonly used for industrial applications due to its high noise
immunity and multi-drop capability. It enables a PC to communicate
with up to 128 instruments over distances of up to 1200m. The
option will require the addition of an RS485 interface card, or a
separate RS232 / RS485 converter.

To
Additional
units

PC com port

DB-9 Pin

To RS485
interface

Insert the nylon screw into the 3mm
diameter hole at the bottom left-hand
corner of the controller board.

Each RS485 interface or converter has specific connection and

Controller 1 Controller 2

termination biasing requirements which will be detailed in their
installation instructions. The general principles are as follows.

Place the spacer over the Nylon
screw thread.

Terminations : Because each wire is a transmission line, it must be
properly terminated to prevent reflections. Where multiple
instruments are daisy chained together a 120Ω resistor should be
fitted at the connection to the PC and to the last instrument in the
chain. (see diagram overleaf). When fitting termination resistors it may

Screw the Nylon nut onto the screw.

Do not overtighten as this will damage
the screw thread.

be necessary to fit bias resistors and an external power supply as the
PC’s integral RS232 port cannot exude sufficient power.

Bias resistors: When transmission lines are not transmitting, they
remain in an indeterminate state which can allow receivers to receive
invalid data bits due to electrical noise on the cable. To prevent this,
the lines should be forced into a known state by fitting two 620Ω
bias resistors to one point (node), see diagram overleaf.

If an RS485 interface card or converter is being fitted to the PC,
separate bias resitors may not be needed because they may already
be fitted to the card. Check the manufacturers specification.

Please note that the KK systems converter supplied by CAL, includes
bias resistors and a jack socket for additional power supply.

As previously mentioned RS485 cards and converters differ greatly in
their requirements and therefore the installation instructions supplied
with the interface should be read carefully.

Bias resistor

620Ω

120Ω 120Ω

620Ω

Bias resistor

Termination resistors

Diagram showing bias and termination resistors

KK Systems K3-ADE TB RS232/485 converter.

If you purchased the KK Systems RS232 / 485 converter from CAL
Controls please refer to ‘ KK Systems K3-ADE TB - Application Guide’
for more details (our document number 33083)

Instrument Comms Settings.

Immediately after power-up, both instrument and PC comms settings
need to be made compatible before communication between them is
possible. Instrument defaults are shown below with available options.
Note: these parameters are found in ‘level C’ of the controller.

ADDR

(Address)

BAUD

(Baud rate)

DATA

(Data)

Settings Start bits Data bits Parity Stop bits

Default 1 8 n (none) 1

Option 1 1 8 e (even) 1

Option 2 1 8 o (odd) 1

DBUG

(Debug)

This is a unique identification number that must
be allocated to each instrument connected to
the network.
Default = 0. Options: 1 to 247

The setting determines the serial
communication data transmission rate in bits/
sec, this must match the PC settings.
Default = 9600. Options: 1200,2400
4800, 9600

19200.
Note: If a comms board has been retro-fitted
the default baud rate is 1200.

Sets the transmission format, this must match
the PC settings.

Data format table

Commissioning and troubleshooting aid. Display
shows when the instrument is transmitting or
receiving data by rapidly flashing three
horizontal segments of the first and last
segments of the display.
First Digit = Tx. Last Digit = Rx
Default = Off Options: off, on.

Only use dbuG during commissioning or trouble-shooting because it
shares display segments and therefore corrupts the normal display.

Configuring instrument comms settings

This should be done immediately after power up and is only possible
from the instrument front panel.

On power-up the controller will display the self test sequence
followed by alternating INPT and NONE

Note: During the following procedure the display will revert to
alternating INPT and NONE after 60 seconds of keying
activity, but will retain any settings already completed. Should this
occur or in the event of becoming ‘lost’ in the program, please start
again from the alternating INPT and NONE display.

To select Level C (communications settings)
Press T once display will alternates with LEVL and 5.
Press and hold À and press T five times to reach LEVL C.

Note: Level C is only visible when the comms interface board is fitted
to the unit.

To set the instrument comms address
Press S once display alternates between ADDR and 0.
Press and hold À and press S to index the chosen address number
(1 to 247)
Note: In the absence of any conflicting information the following
comms settings should be left as default values (see ‘instrument
comms settings’)

To read or adjust comms settings

Baud rate
Press S once display alternates BAUD and 9600
(default setting)
Press and hold À and use S or T keys to select preferred value.

Data Format
Press S once display will alternate DATA and 18N1
(default setting)
Press and hold À and use S or T keys to select preferred setting.

Debug setting
Press S once display alternates DBUG and OFF
(default setting)
Press and hold À and use S key to select ON

To enter settings into memory
Press and hold S and T for 3 seconds, display alternates
INPT and NONE.

To check settings; repeat the above procedure.

The unit is now ready to be configured from the PC.

Note: Where more than one instrument is connected to the system, it
is useful at this point to list them by location, title and comms
address. The list can then be used as a reference to ensure that the
instruments are given the same identity when configuring the comms
link from the PC.

Further Information
Go to www.cal-controls.com for more details.

Modbus communications guide -

programs from PC’s or PLCs.

CALpoll toolkit

code.

Visual Basic toolkit

CALgrafix

for Visual C++ developers include .exe and source

available via [e-mail] .

charting logging and configuration software, which includes

an OPC-based client and server.

For engineers developing their own

Bury Mead Road, Hitchin, Herts, SG5 1RT, UK

CAL Controls Ltd

Tel [phone]
Fax [phone]

e-mail [e-mail]

www.cal-controls.com

1117 S. Milwaukee Av, Libertyville, IL60048, USA

CAL Controls Inc

Tel [phone]

Fax [phone]

e-mail [e-mail]

33010/000M10/06/0106