WI-GTWY-9-xxx Wireless Gateway V1.18
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not respond to the command, then the WI-GTWY-9-xxx will write a ‘FFFF’ value to one of its
own registers, configured under “CF Register” - in this case it is register 4800.
The “Command Type” selected is a write command (you can select read or write) - which
means that the values are sent from the WI-GTWY-9-xxx to the Modbus Slave. The type of
write command is a “Digital” write, meaning that the register values will be written as
digital/binary values”.
If the Modbus Slave device does not respond to the Modbus command, the WI-GTWY-9-xxx
will try another 3 times (“Max Retries” = 3). The Modbus command will be sent to the Modbus
Slave every 100msec. The address of the Modbus Slave is 1 (permissible addresses are 1 – 255).
Because a digital write command has been selected, the destination register type will be digital
outputs, with Modbus tag “0xxxxx”. The first destination Modbus location is 12 (or 00012) -
as there are 6 registers transferred, the destination locations will be 00012 – 00017.
The second example is a register read command to the same Modbus Slave (address 1). The
command requests the Modbus Slave to return the values of 10 registers which will be stored in
I/O registers 463 - 473 in the WI-GTWY-9-xxx. As the command is a “register read” command,
the target Modbus locations will be of the type 3xxxx. The starting location is 30001. So the
values of locations 30001 – 30010 in Modbus Slave 1 will be transferred to I/O registers 463 –
473 in the WI-GTWY-9-xxx.
