Model MCX-32
Model MCX-32 Instruction Manual
Rev.2.3
Page 10 of 49
The state of the contact outputs from field devices are communicated by the DI-4 modules to the controller
using RS-485 Modbus
™
RTU protocol therefore each DI-4 module must have a unique Modbus
™
address.
Modules are serially addressed in hex using the two rotary switches on the module’s front panel labeled MSD
(most significant digit) and LSD (least significant digit). The DI-4 modules must be addressed according to
Table 1 DA-4/DI-4 Modbus Addresses.
A DI-4 module connected properly to the controller will have a flashing DATA COMM LED to indicate a
valid communication status and will provide the controller with a 4mA reading when the contact from the field
device is open and a 20mA reading when the contact is closed for the corresponding channels. All other
information will need to be modified on the Channel Details screen for each channel connected by a DA-4
module.
NOTE:
DI-4 modules can be connected to either Port 1 or Port 2, they must be addressed
correctly and only those channels associated with that DI-4 will be available.
After setting up the correct address for the DI-4 module, the channel needs to be enabled and the information
on the Channels Details screen will need to be modified to reflect the correct sensor type and information.
Setting up a DI-4 should start by selecting the ‘Device Type’ from the Channel Details screen, and selecting
Model DI4 from the ‘DEVICE SELECTION’ screen. If the controller does not detect a DI-4 module, the
controller will display “COMM ERR” in the ‘Status’ field.
A properly addressed DI-4 that is correctly
connected to the controller will respond to channel activation with a mA reading. When the controller has
detected the DI-4, the gas type will default to H2S, the range will default to 100, and the analog out will
default to ‘OFF’. Once the DI-4 has been properly detected, all of the information needed to identify the
sensor can be entered in the Channel Details screen to set the correct parameters for the sensor.
4.3 Analog 4-20mA Outputs (AO-4)
There are four 4-20mA outputs in each Model AO-4 module (See Figure 8). These can be used as signal
inputs to other control devices. AO-4 modules can be installed on the DIN rail of the controller.
4-20mA
Output
COMM
M
S
D
L
S
D
Output 4
Output 3
Output 1
Output 2
There are four
4-20mA outputs on
each AO-4 module.
mA
mA
mA
mA
_
_
_
_
4-20 mA Signal
Input
Control
System
4-20mA
Figure 8
Model AO-4 4-20mA Output Module
AO-4 modules provide a 4-20mA output equal to the current concentration reading reported to the controller
for the associated channel. These concentration readings are communicated by the controller to the AO-4
modules using RS-485 Modbus
™
RTU protocol therefore each AO-4 module must have a unique Modbus
™
address. Modules are serially addressed in hex using the two rotary switches on the module’s front panel
labeled MSD (most significant digit) and LSD (least significant digit). AO-4 modules can be connected to
either Port 1 or Port 2 of the controller. For the controller to recognize the modules, the ‘Analog Out’ on the
Channel Details screen must be turned ‘ON’ for the specific channels associated to the AO-4 modules. The
AO-4 modules must be addressed according to Table 2.
