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AT-MGS-402 User Manual
5. Plug the power terminal block back into the printed circuit board
(PCB).
Figure 3-1 -
Power Terminal Block
L
E
N
3.6 Sensor Output & Modbus Connections
3.6.1 AT-MGS-402 Gas Detection Controller Network
The AT-MGS-402 Modbus communications network is connected to the AT-MGS-410 gas detectors using
a shielded twisted pair instrument cable
(Belden 3106A or equivalent)
. The same type of cable can be used
for power connection when using the AT-MGS-402 controller as the power source
(+24VDC)
for the AT-
MGS-410 gas sensors and standard Modbus network limits. Care needs to be taken to account for voltage
drops between the controller and the AT-MGS-410 gas sensors and standard Modbus network limits. The
furthest distance the AT-MGS-410 can be from the AT-MGS-402 controller is
305M when using 20 - 16AWG
conductors for the sensor power and Modbus connections.
3.6.1.1 Connecting the +24 VDC Terminal Block:
When using the AT-MGS-402 as the +24VDC power source of the AT-MGS-410 gas sensors the power should
be connected the following manner.
1. Locate the +24 VDC terminal block in the AT-MGS-402 controller
(item 11 in “Figure 2-3 - AT-
MGS-402 Layout” on page 7)
.
2. Using Belden 3106A or equivalent control wire feed through one of the available cable glands
and connect the ‘+’ and ‘-‘ terminals to the appropriate terminals in the AT-MGS-402.
NOTE:
Refer to the AT-MGS-410 User Manual or QSG for location and connection of the
corresp24 VDC terminal block in the AT-MGS-410 gas sensor.
