set ia
124 Chapter 2 Command Descriptions
[modbus options]
The configuration options specific to the Modbus protocol, which include:
errorresponse={on|off}
Controls behavior for common run-time errors such as no response
from the slave device. By default, “errorresponse=off” for serial
Modbus protocols, since most masters assume no response when
errors occur. Having this option off also actively filters out returning
Modbus exception codes 0x0A and 0x0B from remote Modbus/TCP
slaves.
broadcast={on|off|replace}
Specifies how to handle incoming requests with a slave address set to
the broadcast value. For Modbus, this is 0. The default is to replace 0
with 1, which was selected to overcome the fact that many Modbus/
TCP clients always send requests to unit ID zero (0) and do not want
this treated as a broadcast.
on
Tells the Digi device to send requests as broadcast to the
destination device(s) and not expect any response message.
offTells the Digi device to throw away the broadcast request.
replace
Changes a broadcast request to a normal request by replacing the
unit ID 0 with a value of 1.
fixedaddress={auto|1-255}
Used to override the Modbus protocol address (unit ID) with a fixed
address.
auto
When set to “auto,” the protocol address will not be overwritten.
1-255
Setting it to a fixed number from 1-255 forces this value to be used
for all Modbus requests.
The default setting is “auto.”