Instruction Manual

Installation and Operation Handbook Installation

2408 and 2404 Controller 1-11

COMMUNICATION MODULES 1 AND 2

All 2408 and 2404 controllers can be fitted with up to two plug-in communications modules.

Only one of the two modules can be for serial communications and this will normally be

installed in position COMMS 1 (although it is possible to install the serial communications

module in position COMMS 2. Serial communications may be configured for either Modbus

or EI bisynch protocol.

It is also possible to fit a PDS module in one or other of these positions.

Possible module types are shown in the table below.

Communications module 1

Terminal identity (COMMS 1)

Module type HA HB HC HD HE HF

2-wire EIA-485 serial

communications

− − −

Common A (+)

B (−)

EIA-232 serial

communications

− − −

Common Rx Tx

4-wire EIA-485 serial

communications

− A′

(Rx+)

B′

(Rx−)

Common

(Tx+)

(Tx−)

PDS Setpoint retransmission

− − − −

Signal Common

Communications module 2

Terminal identity (COMMS 2)

Module type JD JE JF

PDS Setpoint retransmission

−

Signal Common

PDS Setpoint input

−

Signal Common

Table 1-3 Communication modules 1 and 2 connections