Detcon 1640-N4X User Manual

Model 1640-N4X

Gas Detection Unit

Model 1640-N4X

Gas Detection / Alarm System

Operator’s Installation and Instruction Manual

DETCON, Inc.

3200 Research Forest Dr., A-1

The Woodlands, Texas 77381

Ph.281.367.4100 / Fax [phone]

www.detcon.com

August 25, 2009 • Document # 3312 • Revision 0.0

1640-N4X

Page intentionally blank

Shipping Address: 3200 A-1 Research Forest Dr., The Woodlands Texas 77381

Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067

Phone: [phone] • Fax: [phone] •

1640-N4X Instruction Manual ii

www.detcon.com

UH • [e-mail]

1640-N4X

Table of Contents

Introduction .............................................................................................................................................1

1.0

1.1 Serial Sensors (RS-485) ....................................................................................................................... 1

1.2 Analog Sensors (4-20mA).................................................................................................................... 2

2.0 Unit Configuration ..................................................................................................................................3

2.1 Specifications ....................................................................................................................................... 3

3.0 Installation ...............................................................................................................................................5

3.1 Mounting .............................................................................................................................................. 5

3.2 Power and I/O Connections.................................................................................................................. 5

3.3 Initial Power Checks ............................................................................................................................ 8

4.0 Setup .........................................................................................................................................................9

4.1 Front Panel User Interface.................................................................................................................... 9

4.2 Main Menu ........................................................................................................................................... 9

4.2.1 Set Number of Channels ................................................................................................................................10

4.2.2 Set Com 1 Baud Rate..................................................................................................................................... 10

4.2.3 Set Com 2 Baud Rate..................................................................................................................................... 11

4.2.4 Setup Channel Data........................................................................................................................................ 11

4.2.5 Set Channel Alarms .......................................................................................................................................13

4.2.6 Set Relay Function......................................................................................................................................... 14

4.2.7 Set Modbus™ Address .................................................................................................................................. 15

4.2.8 Calibration Mode ........................................................................................................................................... 15

4.2.9 System Diagnostics........................................................................................................................................ 16

4.3 Display Contrast ................................................................................................................................. 16

4.4 Reset Switch ....................................................................................................................................... 16

5.0 Modbus™ Communications.................................................................................................................17

6.0 Trouble-shooting ...................................................................................................................................18

6.1 Sensor Faults ...................................................................................................................................... 18

6.2 Troubleshooting RS485 Networks ..................................................................................................... 18

7.0 Warranty................................................................................................................................................19

Appendix A ........................................................................................................................................................20

RS-485 Unit Integration Wiring..................................................................................................................... 20

Appendix B ........................................................................................................................................................26

Hexadecimal Table......................................................................................................................................... 26

Appendix C ........................................................................................................................................................27

Drawings and Diagrams ..................................................................................Error! Bookmark not defined.

Table of Figures

Figure 1 RS-485 Network Configuration............................................................................................................. 1

Figure 2 DA4 4-20mA Configuration .................................................................................................................. 2

Figure 3 Unit Overview........................................................................................................................................ 4

Figure 4 Dimensional Overview .......................................................................................................................... 5

Figure 5 Typical RS-485 connections.................................................................................................................. 6

Figure 6 Typical Analog Sensor Wiring .............................................................................................................. 7

1640-N4X Instruction Manual iii

1640-N4X

Figure 7 Alarm Relay Connections ...................................................................................................................... 8

Figure 8 Typical Input Power connections........................................................................................................... 8

Figure 9 Front Panel............................................................................................................................................. 9

Figure 10 RS-485 Bus with 4 transceiver chips ................................................................................................. 20

Figure 11 Correct and incorrect wiring schemes................................................................................................ 21

Figure 12 Recommended RS-485 communications set-up ................................................................................ 22

Figure 13 Unbalanced Data Bus......................................................................................................................... 23

Figure 14 Data Bus using two repeaters............................................................................................................. 23

Figure 15 Repeater wiring diagram.................................................................................................................... 23

Figure 16 Daisy Chain wiring diagram .............................................................................................................. 24

Figure 17 Unbalanced Data Bus......................................................................................................................... 24

Figure 18 Four repeater Data Bus ...................................................................................................................... 25

Figure 19 wire length vs. data speed .................................................................................................................. 25

Shipping Address: 3200 A-1 Research Forest Dr., The Woodlands Texas 77381

Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067

Phone: [phone] • Fax: [phone] •

1640-N4X Instruction Manual iv

www.detcon.com • [e-mail]

1640-N4X

1.0 Introduction

The Detcon Model 1640 is specifically designed to serve as a host monitoring and control unit for networks of
gas detection sensors as well as a wide range of other field devices. The NEMA 4X rated enclosure is rain
tight and suitable for mounting in outdoor locations that are deemed electrically non-hazardous environments.

The 1640 Controller is programmed as a Modbus™ master with the capabilities to monitor up to 32 Sensors or
Devices. The unit is capable of monitoring both serial and/or analog Sensors or Devices. Serial devices can
be wired directly to the RS-485 Modbus™. 4-20mA analog devices are monitored via the use of Detcon’s
DA4 Modules.

1.1 Serial Sensors (RS-485)

One method of integration commonly used in industrial applications is the RS-485 serial communications
network, or Modbus™ (Figure 1). RS-485 serial communication is used for multipoint communications and is
a popular choice due to ease of wiring installation. The 1640 is capable of monitoring up to 32 serial devices.

Advantages of using RS-485 serial communication:

¾ Inexpensive method allowing multiple devices to communicate over a single twisted pair of wires.
¾ More data/information can be sent beyond the simple 4-20mA signal.
¾ Transceiver communication up to 4,000 feet without using repeaters.
¾ Highly resistant to induced noise when proper cable and terminations are used.
¾ Two-way (bi-directional), half-duplex, data bus communication consisting of multiple transmitter and

receiver combinations.

Most Units use the RS-485 master/slave architecture for multiple device communication. Each slave unit has
a unique address and responds to data packets generated by the master. The master periodically polls all
connected slave units.

The protocol used by Detcon for the RS-485 communications is the Modbus™ RTU, which is compatible with
most PLC’s, MMI’s, and distributed control Units. The Modbus™ RTU protocol is standard and allows for a
maximum of 32 sensors and/or field devices to be used in this configuration.

Model 1640-N4X

Gas Detection / Alarm System

1 2

Typical Sensors

31 32

Figure 1 RS-485 Network Configuration

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1640-N4X

1.2 Analog Sensors (4-20mA)

Another method of integration is accomplished by using 4-20mA signal output devices with Detcon DA4
Modules (Figure 2). The DA4 Module receives a 4-20mA analog signal corresponding to the range of
detection then changes it to Modbus™ before relaying the information to the 1640 Controller. The Sensor’s
output signal is calibrated so that a 4mA input represents a reading of “0” and a 20mA input represents a
reading of full scale. The scale used for each sensor is user programmable and can be set in the field.
Readings outside the range of 4-20mA will cause a fault, and the unit will display “IN FAULT” for that
device.

Sensor 4

COMM

M
S
D

L
S
D

4-20mA

INPUT

Sensor 3

Typical Sensors

Sensor 1

Sensor 2

Figure 2 DA4 4-20mA Configuration

Analog 4-20mA networks are typically recognized as the most fail-safe approach. When using DA4
Module(s), the 1640 can communicate with up to 32 analog input channels. The enclosure can handle 8 DA4
Modules and associated sensors.

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2.0 Unit Configuration

The Model 1640 is designed to monitor and display the status of up to 32 field sensor devices, provide power,
and programmable alarm outputs. The unit displays real time channel information on a 1” X 5” backlit LCD.
Display information includes the channel number, the gas type, and the gas concentration. The unit will also
display the current Alarm/Fault status via the front panel LED indicators.

The unit is equipped with a set of terminal blocks for A/C input, a set of terminal blocks for the connection of
the RS-485 Modbus™ and power to serial sensors, and a 5-pin plug for the connection of up to 8 Detcon DA4
Analog Sensor Modules that can be mounted inside the enclosure. Alarms are wire via 3-pin plugs directly to
the controller PCA.

2.1 Specifications

Capacity

User Configurable up to 32 devices, Analog and/or Serial

Input

RS-485 Modbus™ RTU (Analog Sensors communicate via the Detcon DA4 Modules)

Accuracy

±1% Full Scale Range

Outputs

User Configurable Relays:
4 relays (Fault, Alarm 1, Alarm 2, and Alarm 3)
Qty 4 Relays: 1 Form C Contacts per relay
Rated for 5A @ 30VDC, 5A @ 250VAC
RS-485 Modbus™ Slave

Power Input

100-240VAC 50~60Hz

Power Consumption

Base Unit <5W – Total Power is dependent on number of I/O modules, number of sensors, and the type
of sensors attached. Total power of the unit, with I/O modules and attached devices, not to exceed 200 Watts.

Display

1” X 5” Backlit LCD

Electrical Classification

NEMA 4X Enclosure

Dimensions

13.85''W x 15.75''H x 6.5''D

Operating Temperature Range

0°C to +45°C

Warranty

One year

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Alarm Relay Terminals

FAULT ALARM3 ALARM2 ALARM1

NC NO NC NO NC NO NC NO

1640 Controller PCA

Front Panel

ACV IN

E

L2

L1

VDC IN

+

S

B

COM 1

A

S

B

COM 2

A

5A

I

O

NEU (L2)

GROUND

Communications

Terminal Blocks

Figure 3 Unit Overview

Ground

Alarm Reset Switch

5A

I

O

B

B

A

A

+

RS-485

RS-485 VDC
Primary

Primary Out

VAC (L1)

Power and

Power
Supply

M
S
D

L
S
D

4-20mA
INPUT

COMM

M
S
D

L
S
D

4-20mA
INPUT

M
S
D

L
S
D

4-20mA
INPUT

M
S
D

L
S
D

4-20mA
INPUT

M
S
D

L
S
D

4-20mA
INPUT

M
S
D

L
S
D

4-20mA
INPUT

M
S
D

L
S
D

4-20mA
INPUT

COMM

COMM

COMM

COMM

COMM

COMM

Up to eight (8)

Customer supplied modules.

M
S
D

L
S
D

4-20mA
INPUT

COMM

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3.0 Installation

The Detcon Model 1640 s a wall-mount enclosure, and can be mounted anywhere that is rated safe for NEMA
4X enclosures. The enclosure is equipped with wall-mounting brackets for easy wall mount installations.

3.1 Mounting

Securely mount the 1640 Enclosure in accordance with Figure 4.

NOTE: AC power should be kept separate from DC power and signals within conduit runs.

Model 1640-N4X

Gas Detection / Alarm System

15.75"14.75"

10"

13.85" 6.85"

Figure 4 Dimensional Overview

Mounting Flanges

6.5"

3.2 Power and I/O Connections

Serial Connections

1. For Serial Units, connect the RS-485 Modbus™ network to the terminal blocks labeled “Primary RS-

485,” “A,” “B,” and “Shld” (Figure 5). Ensure that the network is properly laid out. Proper layout of
the RS-485 network is important for correct operation. Refer to Appendix A (RS-485 Integration and
Wiring) for proper network layouts.

WARNING

more than 4Amps maximum (96 Watts). This equates to about 32 sensors and/or field devices,
maximum. Care should be taken to insure that the total current of equipment utilizing this power does
not exceed the 4Amp rating, as this may cause detrimental damage to the unit and will void the
warranty.

1640-N4X Instruction Manual Rev. 0.0 Page 5 of 28

: The use of the 24VDC output to power external components should be restricted to no

1640-N4X

Note: If there are no I/O Modules installed in the unit, J2 must be plugged into J1 for RS-485
Communication. If I/O Modules are installed in the unit J1 must be plugged into the left most module,
and J2 must be plugged into the right most module for RS-485 Communication.

B

A

+

RS-485 VDC
Primary Out

Figure 5 Typical RS-485 connections

Analog Connections

2. For Analog Sensors, communication is accomplished by using Detcon DA4 modules and the RS-485

Modbus™. The 4-20mA devices are connected directly to the DA4 modules, while the DA4 modules
are connected via the RS-485 Modbus™ to the 1640 (Figure 7). All DA4’s can be mounted within the
enclosure and should be mounted starting from the left moving the ME-Bus End Spacer next to the
Terminal Blocks, and adding modules to the right. Plug the Female Connector (J1) from the RS-485
Output Terminal Blocks onto the Left Most Module. Move the Din-Rail End Stop to the right as
modules are added. Plug the Male RS-485 and Power Connector (J2) into the last module added on
the right. The correct setup of the DA4’s is covered in Section 4.2.4 Setup Channel Data.

COMM

M
S
D

L
S
D

4-20mA

INPUT

Add

Additional
Modules
ass
needed.
Maximum
of 12
Modules.

COMM

M
S
D

L
S
D

4-20mA

INPUT

COMM

M
S
D

L
S
D

4-20mA

INPUT

+

SBA-+

­S

B

RS-485 and Power Cable

A

J1 J2

COMM

M
S
D

L
S

RS-485
Cable to
Output Terminal

D

4-20mA

INPUT

Blocks.

Figure 6 Installing I/O Modules

WARNING

: The 24VDC used to power internal I/O Modules and attached devices is to be restricted

to no more than 4Amps maximum (96 Watts). This equates to approximately 8 DA4 Modules with 32
sensors and/or field devices attached. Care should be taken to insure that the total current of
equipment utilizing this power does not exceed this 4Amp rating, as this may cause detrimental
damage to the unit and will void the warranty.

Note: If there are no I/O Modules installed in the unit, J2 must be plugged into J1 for RS-485
Communication. If I/O Modules are installed in the unit J1 must be plugged into the left most module,
and J2 must be plugged into the right most module for RS-485 Communication.

1640-N4X Instruction Manual Rev. 0.0 Page 6 of 28

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Sensor 4

RS-485 to 1640

COMM

M
S
D

L
S
D

4-20mA

INPUT

Sensor 3

Typical Sensors

Sensor 2

Sensor 1

Figure 7 Typical Analog Sensor Wiring

General Wiring Notes:

 When I/O Modules are located at a remote distance from the controller, an end-of-line terminating resistor

is required to enhance communications reliability. Identify the last I/O Module in the loop, and open the
module casing using the clip release points. Locate and install the jumper on JP6 (TERM) Figure 8. This
adds a 120Ω resistor to the end of the line. If applicable, add a 120Ω resistor to the last Modbus™ gas
sensor.

 Follow generally accepted guidelines for RS-485 serial networks. Do not wire I/O Modules and/or

Modbus™ gas sensors in long-distance ‘T-Tap’ configurations. Stay with direct serial configurations. See
Appendix A for serial communications configuration guidelines.

 Use Detcon Recommended cabling whenever possible.

• Belden P/N 1502P cable is recommended for a single cable providing serial communications and

power.

• Belden 9841 cable is recommended for a single cable providing serial communications only.

 Ground the cable shielding at the Model 1600A-N4X Controller only. Other points of grounding may

cause a ground loop, and induce unwanted noise on the RS-485 line, which in turn may disrupt
communications.

Jumper located

on component

side of PCB

Figure 8 I/O Module Termination jumper (JP6)

3. Connect external annunciators to the relay terminals provided on the back of the 1640 Controller PCA.

The Alarm Relays are labeled “FAULT”, “ALM3” (Alarm 3), “ALM2” (Alarm 2), and “ALM1”

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(Alarm 1). Each relay has a set of dry contacts labeled “COM” Common, “NC” Normally Closed, and
“NO” Normally Open (Figure 9). Wire annunciators to the appropriate alarm/fault relay.

FAULT ALM3 ALM2 ALM1

NC NO NC NO NC NO NC NO

Upper left of Controller PCA

Figure 9 Alarm Relay Connections

4. Connect 110-220VAC input to the Circuit Breakers labeled “VAC (L1)” and “NEU (L2)” and Ground

to the Green/Yellow terminal labeled “GROUND” (Figure 10). The power supply is able to accept
AC input voltages from 100 to 240 volts at 50 or 60Hz.

5A

5A

I

I

O

O

VAC (L1)

NEU (L2)

GROUND

Figure 10 Typical Input Power connections

3.3 Initial Power Checks

To apply power to the unit, turn “ON” both of the Circuit breakers located on the Back Panel, in the lower left
side of the enclosure.

NOTE: Before applying power, check to make sure that all the wiring connections and external
devices are installed correctly.

NOTE: Applying power with devices hooked up incorrectly may cause damage to the equipment.

When power is applied to the unit, the unit will display the firmware revision and properties for several
seconds. For this controller that information should be:

DETCON INC COM 1 MODBUS SLAVE
MODBUS CONTROLLER
VERSION XX.XXX COM 2 MODBUS MASTER
PCWH X.XXX

After unit initialization, the unit will begin normal operation. If the unit has been properly setup, the unit will
display the current status of the devices that are connected to.

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1640-N4X

4.0 Setup

4.1 Front Panel User Interface

The Main Display is a backlit LCD that has 4 lines by 40 characters. In normal operation the channel’s
information will be displayed as “01> XXXX ppm GAS”. If any channel is in an alarm condition, “01>
XXXX IN ALARM ” will be displayed. If any channels are in Fault, they will display “01> XXXX IN
FAULT ”. Any channels are not communicating with the controller will be displayed as “01> XXXX
COMM ERROR ”. Fault and Alarm conditions are also displayed by the use of four (4) LED indicators on the
front panel. The LED’s are labeled ALARM 1 (yellow), ALARM 2 (amber), ALARM 3 (red) and FAULT
(blue).

The 1640 user interface consists of four function keys on the front panel. These keys are labeled: “PROG”,
“u” (Up Arrow), “v” (Down Arrow), and “ENTER”. The “ENTER” key doubles as a “RESET/ACK” key and
is labeled as such.

Model 1640-N4X

Gas Detection / Alarm System

ALM1 ALM2

PROG ENTER

ALM3 FAULT

RESET/ACK

Figure 11 Front Panel

4.2 Main Menu

Unit Setup is accomplished by use of the Main Menu. Parameters for channel data, alarms, relays, and other
functions of the unit can be set via the Main Menu. The correct parameters must be entered into the unit
before the unit will operate properly. The Main Menu consists of 9 items:

SET # OF CHANNELS
SET COM1 BAUD RATE
SET COM2 BAUD RATE
SETUP CHANNEL DATA
SET CHANNEL ALARMS
SET RELAY FUNCTION
SET MODBUS ADDRESS
CALIBRATION MODE

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1640-N4X

SYSTEM DIAGNOSTICS

The “PROG” key is used to enter the Menu Mode of the unit. Upon entering the Main Menu the LCD will
display:

MAIN MENU
SET # OF CHANNELS

Use the “v” (Down Arrow) key to move to the next menu item, or use the “u” (Up Arrow) key to move to the
previous menu item. When the appropriate Menu Item is displayed, use the “ENTER” Key to enter that menu
item. Pressing the “PROG” key again will return the unit to normal operation.

NOTE: The 1640 will automatically time out of Menu Mode and return to the Main Display after 15
seconds of inactivity.

NOTE: Device readings are not updated while the unit is in Menu Mode.

4.2.1 Set Number of Channels

The “SET # OF CHANNELS” menu allows setting the number of active channels to be monitored. The
number of active channels should match the number of sensors or devices being connected and can not exceed
the input capacity of 32 channels.

To enter the “SET # OF CHANNELS” Menu, press the “PROG” key to enter the Main Menu. From the Main
Menu, press the “ENTER” key to enter the “SET # OF CHANNELS” menu. The display will change to
“NUMBER OF CHANNELS:” followed by the number of currently active channels. Use the “u” (Up Arrow)
to increase the number of channels, and the “v” (Down Arrow) key to decrease the number of channels to be
monitored. When the appropriate number of channels is selected, press the “ENTER” key to accept the
number.

Press the “PROG” key to exit the menu and use the “v” key to move to the next menu item, use the “PROG”
key to exit the Main Menu, or allow the unit to time out and the unit will return to Normal Operation after
about 15 seconds.

4.2.2 Set Com 1 Baud Rate

The “SET COM1 BAUD RATE” menu allows setting the communications baud rate for communications port

1. The Baud rate can be set to 4800, 9600, 14400, or 19200. The normal Baud rate is set to 9600 Baud, and
should not be changed.

From the Main Menu use the “u” or “v” keys to move to the “SET COM1 BAUD RATE” menu item and
press “ENTER” to enter the “SET COM1 BAUN RATE” menu. The display will change to “BAUD RATE
COM 1:” followed by the current Baud Rate setting. Use the “u” key to increase the Baud rate, and the “v”
key to decrease the Baud rate. When the appropriate Baud is selected, press the “ENTER” key to accept the
number. The display will return to “SET COM1 BAUD RATE”

Press the “PROG” key to exit the menu and use the “u” or “v” keys to move to the next or previous menu
item, use the “PROG” key to exit the Main Menu, or allow the unit to time out and the unit will return to
Normal Operation after about 15 seconds.

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1640-N4X

4.2.3 Set Com 2 Baud Rate

The “SET COM3 BAUD RATE” menu allows setting the communications baud rate for communications port

2. The Baud rate can be set to 4800, 9600, 14400, or 19200. The normal Baud rate is set to 9600 Baud, and
should not be changed.

From the Main Menu use the “u” or “v” keys to move to the “SET COM2 BAUD RATE” menu item and
press “ENTER” to enter the “SET COM2 BAUN RATE” menu. The display will change to “BAUD RATE
COM 2:” followed by the current Baud Rate setting. Use the “u” key to increase the Baud rate, and the “v”
key to decrease the Baud rate. When the appropriate Baud is selected, press the “ENTER” key to accept the
number. The display will return to “SET COM2 BAUD RATE”

Press the “PROG” key to exit the menu and use the “u” or “v” keys to move to the next or previous menu
item, use the “PROG” key to exit the Main Menu, or allow the unit to time out and the unit will return to
Normal Operation after about 15 seconds.

4.2.4 Setup Channel Data

This menu item allows the setup of parameters necessary for monitoring each device. The parameters set for
each channel should match those of the device that the channel is monitoring.

From the Main Menu use the “u” or “v” keys to move to the “SET CHANNEL DATA” menu item and press
the “ENTER” key to enter the “SET CHANNLE DATA” menu. The LCD will display the current parameters
for Channel 1. In example:

CHANNEL 1 DATA: DECIMAL POINT:0
SLAVE ID:01 RANGE:100
REGS TO READ:13 TYPE:PPM H2S
READING REG:0 RTO:1000 IPD:150

These parameters must be set correctly for each sensor or DA4 module that is connected to the unit. Use the
“u” or “v” keys to move through the parameters, setting the appropriate values for each parameter as described
below. When the Blinking Cursor is positioned over the colon (“:”) of the parameter to be changed, use the
“ENTER” key to make changes to the parameter. The parameter will be displayed in brackets “[ ]” to signify
the ability to change that parameter. Once the correct parameter has been set, use the “ENTER” key to accept
the change. The Cursor will change back to a Blinking Cursor, and the arrow keys can again be used to move
through the parameters.

When the Blinking Cursor is at the end of a set of parameters for one channel, the “v” key will move the
cursor to the next channel’s set of parameters. Likewise, when the Blinking Cursor is at the beginning of a set
of parameters for a channel, the “u” key will move the cursor to the previous channel’s set of parameters.

Note: The parameter screen(s) will not move from the last channel to the first channel, or from the first
channel to the last channel by use of the “u” or “v” keys. The last channel available is determined by the
number of channels set active via the “SET # OF CHANNELS” menu.

SLAVE ID (Slave ID Number):

This is the Modbus™ Hexadecimal address assigned to the sensor and or DA4 Modules connected to the unit.
This number is adjustable from 01 to 7F hex by use of the “u” or “v” keys, and should match the appropriate
device. Each device’s Modbus™ address must be unique. When working with the DA4 modules, it is
important to realize that the DA4 may have 4 analog sensors attached to it, but the DA4 Module has one
Modbus™ address, and that address must be unique. Normally these Modbus™ addresses start at 02 hex and
sequentially increment to the highest address used.

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1640-N4X

REGS TO READ (Registers to read):

This is pre-programmed to the value of 6 and should not be altered unless directed to do so by Detcon Factory
Personnel.

READING REG (Reading Register):

This is pre-programmed to the value of 2 and should not be altered unless using a DA4 Module to monitor
analog 4-20mA devices (such as analog sensors). When using a DA4, this parameter must be modified to
reflect the sensor to the associated DA4 Module. When reading a serial device, this parameter should always
be set to 2.

When setting the parameters for an analog device that is attached to a DA4 Module, the Modbus™ address of
the DA4 Module must be entered as the parameter for the “Slave ID”. The Reading Register parameter should
be changed to reflect the Sensor Number on the DA4 Module to which the device is attached. This Sensor
Number can be identified by the label on the side of the DA4. The value that should be entered into the
Reading Register parameter can be found in the following table:

DA4 Module 1640 Parameters

DA4 Modbus™ Address Sensor Number 1640 Channel Number Slave ID Reading Reg.

01hex Sensor 1 1 01 2
01hex Sensor 2 2 01 3
01hex Sensor 3 3 01 4
01hex Sensor 4 4 01 5
02hex Sensor 1 5 02 2
02hex Sensor 2 6 02 3
02hex Sensor 3 7 02 4
02hex Sensor 4 8 02 5
03hex Sensor 1 9 03 2
03hex Sensor 2 10 03 3
03hex Sensor 3 11 03 4
03hex Sensor 4 12 03 5

… … … … …
08hex Sensor s 1 29 08 2
08hex Sensor 2 30 08 3
08hex Sensor 3 31 08 4
08hex Sensor 4 32 08 5

In Example: If an Analog device is attached to a DA4 Module Sensor 2, and the Modbus™ address of the DA4
is 04 hex, the Slave ID should be set to 04, and the Reading Reg. should be set to 03.

DECIMAL POINT:

This parameter should be set to match the devices display format. Use the “u” or “v” keys to set decimal point
in the correct place in the display. I.E. a decimal point of 0 would provide a display of 100, a decimal point of
1 would provide a display of 10.0, and a decimal point of two would provide a display of 1.00. When the
appropriate decimal point has been selected, use the “ENTER” key to accept the change.

RANGE:

This parameter should be set to match the devices full-scale range. Use the “u” or “v” keys to set the
appropriate range. When the appropriate range has been selected, use the “ENTER” key to accept the value.

When setting the range of a device, it is important to set both the decimal value and the range correctly. The
range display should match that of the device that is connected to that channel. I.E. a range of 1% that has is

1640-N4X Instruction Manual Rev. 0.0 Page 12 of 28

1640-N4X

displayed on the device as 1.00 should be entered as 2 decimal points, with 1.00 entered as the range. This
will provide the correct readout if entered correctly. If the device has a range of 5PPM and is displayed on the
device as 5.00, the range should be entered as 2 decimal points with a Range of 5.00. This will provide a
reading of 5.00 on the display as the range. A range of 50 that is displayed as 50.0 should be entered as one
decimal point and a range of 50.0. A range of 50, that is displayed on the device as 50 (with no decimal
places), should be entered as 0 decimal places, and a range of 50. Entering the range before entering the
decimal point value may cause inaccurate results. Entering incorrect parameters for decimal point and range
will cause inaccurate results.

NOTE: Setting the range or the decimal point incorrectly will limit the setting of the alarm levels, and
cause the unit to operate incorrectly.

TYPE:

This parameter should be set to match the type of device connected. The “TYPE” parameter is an
alphanumeric display of 9 characters that can be changed by use of the “Arrow” keys (“u”, “v”). When the
appropriate alphanumeric character is found press the “ENTER” key to accept that character and move to the
next character position. When all characters have been set (including spaces) the parameter will be updated
and the cursor will change back to a Blinking Cursor.

RTO (Response Time Out):

This is pre-programmed to the value of 500 and should not be altered unless directed to do so by Detcon
Factory Personnel.

IPD (Interpoll Delay):

This is pre-programmed to the value of 50 and should not be altered unless directed to do so by Detcon
Factory Personnel.

When the Blinking Cursor is at the end of a set of parameters for one channel, use the “v” (Down Arrow) key
will move the Blinking Cursor to the next channel’s set of parameters. Continue on to set all of the parameters
for each device.

NOTE: Each device’s parameters must be set correctly for the 1640 to operate properly.

When all of the channels parameters have been set properly, press the “PROG” key to exit the menu and use
the “u” or “v” keys to move to the next or previous menu item, use the “PROG” key to exit the Main Menu, or
allow the unit to time out and the unit will return to Normal Operation after about 15 seconds.

4.2.5 Set Channel Alarms

This menu item allows the setup of Alarm Levels and whether the alarm is ascending or descending. The
parameters set for each channel should be set appropriately for the device that the channel is monitoring.

From the Main Menu use the “u” or “v” keys to move to the “SET CHANNEL ALARMS” menu item and
press the “ENTER” key to enter the “SET CHANNEL ALARMS” menu. The LCD will display the current
parameters for Channel 1. In example:

CHANNEL 1 ALARMS ALM2 LEVEL: 40
ALM2 ASCENDING:Y
ALM1 LEVEL: 20 ALM3 LEVEL: 60
ALM1 ASCENDING:Y ALM3 ASCENDING:Y

The alarm parameters must be set correctly for each sensor that is attached. Use the “u” or “v” keys to move
through the parameters, setting the appropriate values for each parameter as described below. When the

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Blinking Cursor is positioned over the colon (“:”) of the parameter to be changed, use the “ENTER” key to
make changes to the parameter. The parameter will be displayed in brackets “[ ]” to signify the ability to
change that parameter. Once the correct parameter has been set, use the “ENTER” key to accept the change.
The Cursor will change back to a Blinking Cursor, and the arrow keys can again be used to move through the
parameters.

NOTE: Each channels Range and Decimal point values, in the “SET CHANNEL DATA” menu, must be
set properly before that channels alarm parameters can be set.

When the Blinking Cursor is at the end of a set of parameters for one channel, the “v” key will move the
cursor to the next channel’s set of parameters. Likewise, when the Blinking Cursor is at the beginning of a set
of parameters for a channel, the “u” key will move the cursor to the previous channel’s set of parameters.

NOTE: The parameter screen(s) will not move from the last channel to the first channel, or from the first
channel to the last channel by use of the “u” or “v” keys. The last channel available is determined by the
number of channels set active via the “SET # OF CHANNELS” menu.

ALM LEVEL:

Alarms 1, 2 and 3 are all set in the same manner. This parameter is used to set the alarm point for each alarm.
The alarm level is adjustable from 1 to the maximum range set in the “RANGE” parameter of the “SET
CHANNEL DATA” menu for the sensor selected. (I.E. if the sensor range is 1000, the maximum set point for
the alarm would be 1000.) Use the “u” or “v” keys to set the appropriate value for the alarm set point. Use
the “ENTER” key to accept the value. Set the alarm level set points for alarms 1, 2 and 3.

NOTE: Each channels Range and Decimal point values, in the “SET CHANNEL DATA” menu, must be
set properly before that channels alarm parameters can be set properly.

ALM1 ASCENDING:

This parameter is used to set the alarms as ascending or descending. Alarms 1, 2 and 3 are all set in the same
manner. Use the “u” or “v” keys to change the value from “Y” (yes) to “N” (no). Set to “Y”, the alarm will
be set as ascending, set to “N”, the alarm will bet set to descending. Use the “ENTER” key to accept the
value. Set the Alarm Ascending parameter appropriately for alarms 1, 2, and 3.

When the Blinking Cursor is at the end of a set of parameters for one channel, use the “v” (Down Arrow) key
to move the Blinking Cursor to the next channel’s set of parameters. Continue on to set all of the parameters
for each sensor.

NOTE: Each device’s alarm parameters must be set correctly for the unit to function properly.

When all of the channels parameters have been set properly, press the “PROG” key to exit the menu and use
the “u” or “v” keys to move to the next or previous menu item, use the “PROG” key to exit the Main Menu, or
allow the unit to time out and the unit will return to Normal Operation after about 15 seconds.

4.2.6 Set Relay Function

“SET RELAY FUNCTION” allows the relays to be set as Latching/Non-Latching, Energized/De-Energized,
and Silanceable/Non-Silenceable. The menu item will go through all 4 relay settings starting with the Fault
Relay, and continuing on through Alarm 1, Alarm 2, and Alarm 3 Relays.

From the Main Menu use the “u” or “v” keys to move to the “SET RELAY FUNCTION” menu item and
press the “ENTER” key to enter the “SET RELAY FUNCTION” menu. The LCD will display the current
parameters for the Fault Relay:

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FAULT RELAY SETUP
LATCHING:Y
ENERGIZED:Y
SILENCABLE:Y

Use the “u” or “v” keys to move through the parameters, setting the appropriate values for each parameter as
described below. When the Blinking Cursor is positioned over the colon (“:”) of the parameter to be changed,
use the “ENTER” key to make changes to the parameter. The parameter will be displayed in brackets “[ ]” to
signify the ability to change that parameter. Once the correct parameter has been set, use the “ENTER” key to
accept the change. The Cursor will change back to a Blinking Cursor, and the arrow keys can again be used to
move through the parameters.

When the Blinking Cursor is at the end of a set of parameters for one relay, the “v” key will move the cursor to
the next relays set of parameters. Likewise, when the Blinking Cursor is at the beginning of a set of
parameters for a channel, the “u” key will move the cursor to the previous relays set of parameters.

NOTE: The parameter screen(s) will not move from the Alarm 3 Relay to the Fault Relay, or from the
Fault Relay to the Alarm 3 Relay by use of the “u” or “v” keys.

Latching
The latching parameter will determine if the relay will clear itself when a Fault or Alarm condition has passed.
If a relay is set to latching, and the relay is set to energize upon an alarm, the alarm will remain energized until
the alarm condition has passed, and the alarm is reset by use of the “RESET” switch or key. To set a relay as
latching, set the “LATCHING:” parameter to “Y”.

Energized
The energized parameter will determine if the relay is set as energized or de-energized. If a relay is set as
energized, the relay will have a normal state of being energized. When an Alarm or Fault occurs the
associated relay will de-energize. To set a relay as energized, set the “ENERGIZED:” parameter to “Y”.

Silencable
The silencable parameter will determine if a relay can be silenced if an alarm or fault condition is present. If a
relay is set as silencable, then the relay can be reset to the normal state even if the alarm or fault condition is
still present. To set a relay as silencable, set the “SILENCABLE:” parameter to “Y”.

When all of the relay parameters have been set properly, press the “PROG” key to exit the menu and use the
“u” or “v” keys to move to the next or previous menu item, use the “PROG” key to exit the Main Menu, or
allow the unit to time out and the unit will return to Normal Operation after about 15 seconds.

4.2.7 Set Modbus™ Address

Allows the Modbus™ address of the unit to be changed. This address should not be changed unless directed
to do so by Detcon Factory Personnel.

4.2.8 Calibration Mode

“CALIBRATION MODE” disables all alarms until the calibration mode is exited.

To enter the “CALIBRATION MODE” Menu item, press the “PROG” key to enter the Main Menu. From the
Main Menu, press the “v” (Down Arrow) key until the display shows “CALIBRATION MODE”. Press the
ENTER” key to enter calibration mode.

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The relays and alarm LED’s will remain disabled until the “ENTER” key is pressed again, “CALIBRATION
MODE” is exited, and the unit returns to normal operation.

NOTE: The 1640 does not poll devices while in Menu Mode, so there are no updates to displayed
readings or alarms.

Press the “PROG” key to exit the Main Manu, or use the “u” or “v” keys to move to the next or previous menu
item.

4.2.9 System Diagnostics

The unit will perform a series of tests to insure the integrity of the firmware and hardware. System diagnostics
should not be run in the field unless directed to do so by Detcon Factory Personnel.

4.3 Display Contrast

The Contrast Potentiometer located on the right hand side of the PCB adjusts the display contrast. The
Potentiometer is labeled “CONTRAST”.

4.4 Reset Switch

The “RESET” Switch located on the right side of the unit is used to reset alarms, and if the parameters are set
properly the switch will silence alarms.

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5.0 Modbus™ Communications

The 1640 Controller features a Modbus compatible communications protocol and is addressable by a PLC,
PC/HMI, DCS, or other Modbus RTU master-polling devices. Communication is accomplished by two wire
half duplex RS-485, 9600 baud, 8 data bits, 1 stop bit, no parity, through the controller COM1 connection port
(P3). The Slave ID number is defaulted to 01Hex.

Modbus™ Register Detail:
Code 03 - Read Holding Registers, is the only code supported by the 1640.

Register #
40000 Channel 1 Reading
40001 Channel 2 Reading
40002 Channel 3 Reading
40003 Channel 4 Reading
40004 Channel 5 Reading
40005 Channel 6 Reading
40006 Channel 7 Reading
40007 Channel 8 Reading
40008 Channel 9 Reading
40009 Channel 10 Reading
4000A Channel 11 Reading
4000B Channel 12 Reading
4000C Channel 13 Reading
4000D Channel 14 Reading
4000E Channel 15 Reading
4000F Channel 16 Reading
40010 Channel 17 Reading
40011 Channel 18 Reading
40012 Channel 19 Reading
40013 Channel 20 Reading
40014 Channel 21 Reading
40015 Channel 22 Reading
40016 Channel 23 Reading
40017 Channel 24 Reading
40018 Channel 25 Reading
40019 Channel 26 Reading
4001A Channel 27 Reading
4001B Channel 28 Reading
4001C Channel 29 Reading
4001D Channel 30 Reading
4001E Channel 31 Reading
4001F Channel 32 Reading

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6.0 Trouble-shooting

6.1 Sensor Faults

The unit is set up such that Sensor faults will set Fault alarms associated with that sensor. If a sensor goes into
a fault condition, that channel will flag a fault. From the “Main Screen” each channel can be quickly viewed
to see which channel is causing the fault. That sensor should be then checked to find the cause of the fault.
Faults are logged in the Alarm History for aid in tracing intermittent sensor problems. Refer to the appropriate
sensor manual for more information on trouble-shooting sensor faults.

6.2 Troubleshooting RS485 Networks

The first step in finding the bad device or several bad devices is to start at the master:

1. Disconnect the data cable bus wires going to all of the slave devices from the output terminal blocks

(A and B).

2. Connect a known working slave device directly to the master (attached directly to the output terminal

blocks) and make sure that it is functional. If it is not, replace the 1640 Controller PCA.

3. Disconnect the working device connected in Step 2, and re-connect the data cable bus wires (A&B) to

the master.

4. Use a voltmeter to measure the voltage across the A and B wires and write the reading down. This

reading should be 400-500mV.

5. Go to the first slave device. Re-connect or plug the device in and measure the voltage across A and B.

Write down the reading. The measurement taken should be 400 to 500mV. If the voltage is not
within the specified range, verify that all devices have been unplugged from the data bus.

6. Unplug the first device and proceed to the next slave device. Record the meter readings. Again the

reading should be 400-500mV. If the reading is not 400-500mV a wiring problem may exist, or the
transmitter may be non-operational.

7. Repeat the procedure with each slave device, recording the readings along the way. If any of the other

readings taken are above or below the first reading by more than 50mV that unit’s transmitter or the
module should be replaced.

Results similar to those

shown here should be

expected. In this example

slave device 03 and 0B

would need to be changed.

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Slave Master MV Difference

ID 01 425 451 26
ID 02 425 430 5
ID 03 425 486 61
ID 04 425 410 -15
ID 05 425 420 -5
ID 06 425 432 7
ID 07 425 422 -3
ID 08 425 415 10
ID 09 425 418 -7
ID 0A 425 440 15
ID 0B 425 310 115

1640-N4X

Measuring at the master device between dc common and A, or dc common and B should give a reading of
around 2.5vdc. Remember this is with the power on, but with no communication taking place.

Another method of troubleshooting is to enable the communications and remove all the slaves. Proceed to
plug 1 slave in and see if communication is good. If so, plug in the next slave and check again.

Repeat this with each slave until all of the slaves are plugged in or one of the slaves takes the data bus down.
The following table consists of recommended cables and their specifications from Belden. These cables are
designed with RS-485 in mind and should be used for RS-485 data buses.

Belden# pairs AWG Impedance

9841 1 24 120ohm

9842 2 24 120ohm

8132 2 28 120ohm

The root cause of many RS-485 communication problems can be traced back to incorrect cabling, incorrect
cable and wire types, and the use of incorrect wiring schemes. It is easier to avoid these problems by
following a few simple guidelines:

9 Use good wiring schemes (refer to Appendix A).
9 Use recommended cables.
9 Properly connect data lines and shields.
9 Insure proper termination of data lines.
9 Use isolated repeaters to avoid grounding problems.

7.0 Warranty

Detcon Inc., as manufacturer, warrants each new 1640 Control Unit to be free from defects in material and
workmanship under intended normal use for a period of one year. The warranty period begins on the date of
shipment to the original purchaser and ends one year thereafter.

All warranties are FOB the Detcon factory. Should any product fail to perform in accordance with published
specifications within the warranty period, return it freight pre-paid to Detcon Inc., 3200 Research Forest Drive
Suite A-1, The Woodlands, Texas 77381 for necessary repairs.

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Appendix A

RS-485 Unit Integration Wiring

RS-485 is a generic electrical specification only. It does not specify connector types, protocols, or cable type.
It is the responsibility of the installer to provide a correct physical installation for the RS-485 network to
function properly.

RS-485 is very inexpensive and inherently rugged, allowing multiple devices to communicate over a single
twisted pair of wires. Detcon has chosen to implement the Modbus™ protocol using the RS-485 electrical
specification.

RS-485 is a two way half-duplex data bus made up of a transceiver (transmitter and receiver). In its simplest
form, one transceiver is located on each end of a twisted pair cable of up to 4,000 feet maximum. Data can be
sent in either direction, but can only be sent in one direction at a time.

The specification allows for the connection of up to 40 unit loads (UL’s) to the twisted pair. An older
transceiver chip would have represented 1 UL. Connection of more than 40 UL’s to the bus will limit the
drivers and cause attenuation of the signal, thus preventing the Unit from operating properly.

Since RS-485 allows multiple devices to be connected to the bus, wiring is not as straightforward as it is in a
bus with only 2 devices. The best wiring scheme is the daisy-chain connection from device 1 to device 2 to
device 3 to device n. All devices that tap into the bus should not be at the end of long stubs, branches, or t­taps. A true daisy-chain has direct wiring between devices with no minor branches.

Detcon equipment contains four wiring terminals for RS-485 connections. Two for A(+) and two for B(-). All
connections should be made directly to these. Figure 3.1 shows an electrical representation of a simple RS­485 bus with 4 transceiver chips.

Figure 12 RS-485 Bus with 4 transceiver chips

The use of a daisy-chain connection will perform the best in all applications given the bus is properly
terminated. The RS-485 standard specifies the transceiver characteristics only, not the interconnection of the
transceivers themselves. Depending on the environment, distance and other factors it is possible to connect
transceivers using flat cable, twisted pair cable, even PCB traces. However, for the most reliable data transfer
in industrial environments, shielded twisted pair is required. Wiring of 24 AWG is highly recommended, but
18 to 28AWG can be used.

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The characteristic impedance of the cable must be between 100 to 120 ohms. Twisted pair is used because if
the cable does run near a noise source both conductors will pick up the same amount of noise; therefore,
effectively canceling it out.

Incorrect Wiring Schemes

Among the biggest problems with an RS-485 bus is the use of incorrect wiring schemes mixed with improper
or no line termination.

Most existing installations do not have wire runs in a daisy-chain like fashion; instead, wire runs typically
originate from a central point and run to different devices in a star-like pattern. This is a very undesirable way
to wire an RS-485 bus. The chances of problem free operation over the life of the equipment decreases
dramatically the further you stray from a straight daisy-chain wiring scheme. The bus needs to be terminated
at each end of the cable run to operate ideally. Other wiring schemes introduce multiple “cable ends” making
it impossible to balance the lines. Wiring as in Figure 13 (A, B & C) would provide reliable data flow.
Figures D, E & F could possibly work, but would require many repeaters and an experience worker with RS­485 communications and networks knowledge to achieve implementation.

Figure 13 Correct and incorrect wiring schemes

Figure 14 shows a typical RS-485 communication setup using 2-wire digital communication. Each RS-485
loop should have (1) beginning and (1) end, with a 120-ohm resistor at the end of each loop.

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Figure 14 Recommended RS-485 communications set-up

Grounding

Another problem that can occur with RS-485 is incorrect grounding. Neither one of the two conductors in the
cable is ground. Both of the conductors are supplying a current to maintain a voltage level relative to an
external reference. A third conductor must be supplied to establish a reference through earth ground.

RS-485 is specified be able to work normally with a ±7V ground potential difference and survive ±25V surges.
In most applications, the equipment is powered from its own DC power supplies. This is good as long as the
supplies are located in the same physical location, and the DC commons are tied together and tied to earth
ground.

Problems occur when part of the data bus is powered by one supply and the second part of the bus is powered
by a power supply located elsewhere. In this case, earth ground is being relied upon to be the reference
between the two sections of the bus. If noise is induced onto the earth ground of one power supply and not the
other, data errors may occur. This is even more likely to occur when the distance between ground references
is large. A solution to this problem is to install an isolated repeater into the data bus to isolate the grounds
from each other, thus enabling the bus to use only one of the two references.

Isolated Repeaters

Repeaters can play many rolls in the implementation of an RS-485 data bus. Repeaters can: 1) Extend the
distance if needed to go further than 4000 feet. 2) Allow for the addition of more devices to the bus. 3)
Increase signal strength and integrity. 4) Solve grounding problems and solve some of the problems that occur
when an incorrect wiring scheme is implemented.

A repeater consists of two transceivers working together. One transceiver is connected to the main data bus
and the other transceiver connects to the remainder of the devices as it creates a new and separate data bus.
Figure 15 depicts a data bus that implements an undesirable branched wiring scheme. Depending on the
length of the taps of slave 1 and slave 2, they may or may not communicate properly back to the master. Long
lengths of cable to slaves 1 and 2 create four ends to the cable instead of two, which cannot be balanced with
the two terminating resistors on the extreme ends. Without a balanced bus, the long taps of slave 1 & 2 will
introduce reflections to the signal that can lead to problematic operation in the field. These problems can be
very hard to diagnose, isolate, and fix.

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Figure 15 Unbalanced Data Bus

The addition of 2 repeaters (Figure 16) can solve this problem. The repeaters look like short stubs to the main
bus, and at the same time they create 2 new buses that have all the same characteristics as the main bus. Each
leg must have termination resistors to balance the new data bus.

Figure 16 Data Bus using two repeaters

Be sure to check the equipment being installed. Some manufacturers include a built-in terminating resistor
that can be selected by a jumper or dipswitch. Detcon Model 1640 has such a jumper located on the FA-isonet
card. The jumper is labeled “120 ohm Term.”

Detcon 600 series gas sensors and DA1 modules do not include this resistor, and therefore, if one of these
devices is the last on the RS-485 bus, a discrete 120 ohm resistor should be placed across the “A” and “B”
terminals on the connector board. Figure 17 illustrates the wiring scheme of a repeater when used in a wiring
bus with DA-1 devices.

Figure 17 Repeater wiring diagram

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Device Hook-Up

Installation should begin by deciding where devices will be located and how the connections between devices
and the master will be established. The ideal scenario would look like Figure 18. The example shows the
1640 Controller connected to 11 slave devices using a daisy-chain wiring scheme. This would require 2
different twisted pair cables, one pair for power, and the other for the RS-485 data bus.

Connections would be point-to-point starting at the master and running to the last slave. The RS-485 data
cable should come into the sensor enclosure and be connected to the A & B terminals. The next segment of
cable should also connect to the A & B terminals and leave the enclosure headed for the next device. The
shields must be tied together inside the enclosure and not allowed to short to any other wires or surfaces. The
shield should be connected only inside the Model 1640 cabinets to the shield terminal. The Rt label in the
drawing shows where the termination resistors would be installed.

01 02

Control Room

Rt

09

0a

08

Rt

04

0b

07 06

03

05

Figure 18 Daisy Chain wiring diagram

Daisy Chain Wiring is ideal, although wiring may already exist or the wiring cannot be run this way for some
reason. Figure 19 shows a more realistic wiring situation that may occur.

01 02

03

Control Room

09

0a 0b

08

04

05

0607

Figure 19 Unbalanced Data Bus

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In this case it is impossible to balance the data bus because there is no distinct beginning or end to the cable
run. The best way to make this type of installation successful is to install repeaters in a few key areas as
shown in Figure 20. Repeaters are used to eliminate the t-taps or stubs, which can cause communication
problems. The location and number of stubs will dictate where repeaters need to be installed. Four repeaters
are installed to eliminate the stubs.

01 02

Rt

Rt

08

09

repeater #1

repeater #2

Control Room

Rt

0a

repeater #3

Rt

07 06

Rt

Rt

04

Rt

0b

Rt

03

Rt

05

repeater #4

Rt

Figure 20 Four repeater Data Bus

Notice there are 5 different data buses that make up the communications network. The first one consists of the
master located in the control room, device 09, repeater #1, device 01, device 02, repeater #2, device 03, and
device 05. Notice the termination resistors at the beginning and end of this bus section. The second bus starts
at repeater #2. It consists of the repeater and device 04. Since this is a new bus, it has terminating resistors at
each end. The third bus starts at repeater #1. It includes device 08, repeater #3, device 07, repeater #4, and
device 06. It also has its own resistors. The fourth bus starts at repeater #3 and consists of the repeater, device
0A, and the terminating resistors. The fifth bus starts at repeater #4 and consists of the repeater, device 0B,
and termination resistors. This configuration isolates all of the t-tap stubs. This configuration should function
properly as long as the wire type and proper distances are observed.

The following chart shows an approximation of wire length vs. data speed. Detcon operates its equipment at
19,200bps (baud) and lower.

100 mbps

10 mbps

1 mbps

100 kbps

10 kbps

1 kbps

0 ft

10 ft

100 ft

1000 ft

5000 ft

10000 ft

Figure 21 wire length vs. data speed

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Appendix B

Hexadecimal Table

ID# SW1 SW2 ID# SW1 SW2 ID# SW1 SW2 ID# SW1 SW2 ID# SW1 SW2 ID# SW1 SW2

none

10 0 A 53 3 5 96 6 0 139 8 B 182 B 6 225 E 1
11 0 B 54 3 6 97 6 1 140 8 C 183 B 7 226 E 2
12 0 C 55 3 7 98 6 2 141 8 D 184 B 8 227 E 3
13 0 D 56 3 8 99 6 3 142 8 E 185 B 9 228 E 4
14 0 E 57 3 9 100 6 4 143 8 F 186 B A 229 E 5
15 0 F 58 3 A 101 6 5 144 9 0 187 B B 230 E 6
16 1 0 59 3 B 102 6 6 145 9 1 188 B C 231 E 7
17 1 1 60 3 C 103 6 7 146 9 2 189 B D 232 E 8
18 1 2 61 3 D 104 6 8 147 9 3 190 B E 233 E 9
19 1 3 62 3 E 105 6 9 148 9 4 191 B F 234 E A
20 1 4 63 3 F 106 6 A 149 9 5 192 C 0 235 E B
21 1 5 64 4 0 107 6 B 150 9 6 193 C 1 236 E C
22 1 6 65 4 1 108 6 C 151 9 7 194 C 2 237 E D
23 1 7 66 4 2 109 6 D 152 9 8 195 C 3 238 E E
24 1 8 67 4 3 110 6 E 153 9 9 196 C 4 239 F F
25 1 9 68 4 4 111 6 F 154 9 A 197 C 5 240 F 0
26 1 A 69 4 5 112 7 0 155 9 B 198 C 6 241 F 1
27 1 B 70 4 6 113 7 1 156 9 C 199 C 7 242 F 2
28 1 C 71 4 7 114 7 2 157 9 D 200 C 8 243 F 3
29 1 D 72 4 8 115 7 3 158 9 E 201 C 9 244 F 4
30 1 E 73 4 9 116 7 4 159 9 F 202 C A 245 F 5
31 1 F 74 4 A 117 7 5 160 A 0 203 C B 246 F 6
32 2 0 75 4 B 118 7 6 161 A 1 204 C C 247 F 7
33 2 1 76 4 C 119 7 7 162 A 2 205 C D 248 F 8
34 2 2 77 4 D 120 7 8 163 A 3 206 C E 249 F 9
35 2 3 78 4 E 121 7 9 164 A 4 207 C F 250 F A
36 2 4 79 4 F 122 7 A 165 A 5 208 D 0 251 F B
37 2 5 80 5 0 123 7 B 166 A 6 209 D 1 252 F C
38 2 6 81 5 1 124 7 C 167 A 7 210 D 2 253 F D
39 2 7 82 5 2 125 7 D 168 A 8 211 D 3 254 F E
40 2 8 83 5 3 126 7 E 169 A 9 212 D 4 255 F F
41 2 9 84 5 4 127 7 F 170 A A 213 D 5
42 2 A 85 5 5 128 8 0 171 A B 214 D 6

0 0 43 2 B 86 5 6 129 8 1 172 A C 215 D 7
1 0 1 44 2 C 87 5 7 130 8 2 173 A D 216 D 8
2 0 2 45 2 D 88 5 8 131 8 3 174 A E 217 D 9
3 0 3 46 2 E 89 5 9 132 8 4 175 A F 218 D A
4 0 4 47 2 F 90 5 A 133 8 5 176 B 0 219 D B
5 0 5 48 3 0 91 5 B 134 8 6 177 B 1 220 D C
6 0 6 49 3 1 92 5 C 135 8 7 178 B 2 221 D D
7 0 7 50 3 2 93 5 D 136 8 8 179 B 3 222 D E
8 0 8 51 3 3 94 5 E 137 8 9 180 B 4 223 E F
9 0 9 52 3 4 95 5 F 138 8 A 181 B 5 224 E 0

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Appendix C

Revision History

Revision Date Changes made

0.0 08/25/09 Manual Created

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Appendix D

Drawings and Diagrams

1. 1640-N4X Dimensional Overview

2. 1640-N4X Component Layout

3. 1640-N4X Interconnect Wiring Diagram

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