Model MCX-32
Model MCX-32 Instruction Manual
Rev. 2.3
Page 9 of 49
The 4-20mA signals from the sensors are communicated by the DA-4 modules to the controller using RS-485
Modbus
™
RTU protocol therefore each DA-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 DA-4 modules must be addressed according to Table 1
DA-4/DI-4 Modbus Addresses.
A DA-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 continuous reading of the sensor attached.
All other information will need to be modified on the Channel Details screen for each channel connected by a
DA-4 module.
NOTE:
DA-4 modules can be connected to either Port 1 or Port 2, they must be addressed
correctly and only those channels associated with that DA-4 will be available.
After setting up the correct address for the DA-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 DA-4 should start by selecting the ‘Device Type’ from the Channel Details screen, and selecting
Model DA4 from the ‘DEVICE SELECTION’ screen. If the controller does not detect a DA-4 module, the
controller will display “COMM ERR” in the ‘Status’ field. A properly addressed DA-4 that is correctly
connected to the controller will respond to channel activation with a concentration reading.
When the
controller has detected the DA-4, the gas type will default to H2S, the range will default to 100, and the analog
out will default to ‘OFF’. Once the DA-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.
4.2 Dry Contact Inputs (DI-4)
Relay contact outputs from field devices can be connected to Model DI-4 input modules. There are four relay
contact inputs in each Model DI-4 module (See Figure 7). DI-4 modules can be installed on the DIN rail of
the controller. DI-4 modules can be connected to either Port 1 or Port 2 of the controller.
CONTACT
INPUT
COMM
M
S
D
L
S
D
NO
NC
COM
Relay Contacts
Input 4
Input 3
Input 1
Input 2
There are four relay
contact inputs on
each DI-4 module.
mA
+
mA
+
+
mA
+
mA
NO
NC
COM
Relay Contacts
4mA Reading
20mA Reading
Figure 7
Model DI-4 Contact Input Module
