Tm-Th8 Notes; Protocol Switching - ICP DAS USA tM-TH8 User Manual

1.12 tM-TH8 Notes

The Modbus RTU communication protocol is the default
protocol of the tM series. The communication Baud Rates
for the Modbus RTU protocol can be in the range of 1200
bps to 115200 bps
Modbus functions supported by the module are described
in Chapter 3.

1.12.1 Protocol Switching

To switch to the DCON protocol:
1. Uses sub-function 06h of the function 46h and set byte
8 to a value of 1. See Section 3.6.4 for details. Or, set
both of the Modbus registers 00257 and 00258 to zero.
2. After a power-on reset, the communication protocol
will be changed to DCON.
To switch to the Modbus RTU protocol:
1. Sends the $AAPN command and set N to a value of 1.
Note that for the tM-TH8, the slide switch of the
module should be set to the INIT position, see the
figure on the next page. See Section 2.17 for details.
2. After a power-on reset, the communication protocol
will be changed to the Modbus RTU protocol.
24 tM-TH8 User Manual, Rev: A1.1 7MH-018-A11