Samson 3374 Series - Page 61

EB 8331-4 EN 7-11
Start-up and conguration
For Modbus RTU communication, the RS-485 module (order no. 1402-1522) must be insert-
ed into the actuator.
Î ExcerptfromModbuslist:seeAnnexA.
Protocol
− Setting: automatic
The SSP and Modbus RTU protocols are automatically detected: the interface parameters
arexedinternallytoBaudrate9600bit/s,8databits,noparity,1stopbit.Theelectric
actuator can exchange data with TROVIS-VIEW or the control station without switching
over. The station address and bus failure monitoring are adjustable.
− Setting: Modbus RTU
Communication is based on the Modbus RTU protocol. All interface parameters listed in
Table 7-1 are adjustable.
Station address (Code A64)
The station number is used to identify the electric actuator for the Modbus RTU protocol.
Baud rate (Code A65)
Itisthetransmissionratebetweentheelectricactuatorandcontrolstation/computer.The
Baudrateadjustedattheelectricactuatormustbethesameasthatinthecontrolstation.
Otherwise, no communication is established.
Stop bit and parity (Code A66)
The number of stop bits and the parity are set in Code A66. The parity is used to detect data
transmission errors. The parity bit is added to the end of the string of data bits and the total
value is made up from the data and parity bit.
Bus failure monitoring (Code A67)
The external manual level of the communication is monitored by the bus failure monitoring
(timeout). After a bus failure is detected, automatic operation is reestablished. The time for
the bus failure monitoring is adjustable. Set the value to 0 to deactivate bus failure monitor-
ing.