Excerpt From Modbus List - Samson TROVIS 5724-8 Series Mounting And Operating Instructions

Annex

10.3 Excerpt from Modbus list

The firmware version 2.1x of TROVIS 5724-8 and TROVIS 5725-8 Electric Actuators with
Process Controller have an integrated RS-485 interface to use the Modbus RTU protocol,
which is a master/slave protocol (in which the control station acts as the master and the elec-
tric actuator as the slave).
The following Modbus functions are supported:
Code Modbus function
1 Read Coils
3 Read Holding Registers
5 Write Single Coil
6 Write Single Register
15 Write Multiple Coils
16 Write Multiple Registers
The electric actuator can issue the following Modbus error responses:
Error code Error
1 Illegal function
2 Illegal data address
3 Illegal data value
4 Slave device failure
6 Slave device busy
Several important data points from the Modbus data point list are listed below. The entire da-
ta point list is available on request.
NOTICE
!
Data are saved in a non-volatile EEPROM. This type of memory has a limited life of at least
one million write operations per memory address. It is almost impossible to exceed this lim-
itation if configurations and data are only changed manually using TROVIS-VIEW or the
keys on the device. If parameters are changed automatically (e.g. by Modbus communica-
tion), make sure to observe the maximum number of write operations and take appropriate
action to prevent that parameters are written too frequently.
48
Application
Read state of several digital outputs in bit format
Read several parameters
Write a single digital output in bit format
Write a value into a single holding register
Write several digital outputs in bit format
Write a value into several holding registers
Cause
The function code is not supported.
A register address is invalid or write-protected
A value contained in the data is not allowed or not
plausible.
An unrecoverable error occurred during an action.
The slave is busy and cannot accept the query.
EB 5724-8 EN