Gill Instruments Ltd
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MaxiMet
Page 23
Issue 3
Doc. No. 1957-PS-021
May 2018
4.7.
Connecting to a PC using RS422 (Not a default setting)
MaxiMet default factory comms setting is RS232
To use the MaxiMet with RS422 comms use MetSet to change the COMMS interface setting to
RS422
Alternatively, use MetSet to change the COMMS interface setting to EXT and leave connector Pin
8 open circuit
If EXT is selected and Pin 8 connected to Pin 2 supply positive then COMMS will change to RS232
MaxiMet
9-Way Connector
PC with RS422
Converter
Signal Names
Pin
Nos.
Cable – 4 twisted
pairs
Signal Names
TXD +
TXD –
4
5
RXD +
RXD –
RXD +
RXD –
6
7
TXD +
TXD –
Signal Ground
1
Signal Ground
Not connected this
end
N/A
Screen and drain
wires
Chassis Ground
Comms
8
V
V supply -
2
3
+
–
DC power supply
4.8.
Using RS485 (not a default setting)
MaxiMet default factory comms setting is RS232.
To use the MaxiMet with RS485 2 wire communication use MetSet to change the COMMS
Interface setting to RS485P 2W.
For Gill ASCII two wire point to point only mode use MetSet to change the Message setting from
CONT (Continuous) to POLL, the node address letter may be changed if required.
For RS485 two wire fully networkable Modbus Mode leave the Message setting in CONT
(Continuous).
Leave connector Pin 8 open circuit.
MaxiMet9-Way Connector
PC with RS485 Card
Signal Names
Pin
Nos.
Cable – 3 twisted pairs
Signal Names
TXD+
RXD+
4
6
T/RXD +
T/RXD –
TXD –
RXD –
5
7
Signal Ground
1
Signal Ground
Not connected
this end
N/A
Screen and drain wires
Chassis Ground
COMMS
8
V
V supply -
2
3
+
–
DC power supply
