Manual

Trusted
TM
Communication Interface T8151B
Issue 21 Apr 10 PD-T8151B 25
The following tables list the valid values for each of the control and status register types. In all cases
invalid values written to the control registers result in the inactive state being selected.
State Value Description
Inactive 0
Set link inactive, stop communications, set
slaves unavailable
Standby 1 Set link active but do not transfer data
Active 2 Set link active and transfer data
Table 4 Modbus Master Control register
State Value Description
Healthy 0 Link is active, no errors reported
Initialising 1
Link is not yet established or has failed,
slaves are unavailable
Error 2 Software error in communications module
Table 5 Modbus Master Status Register