Samson TROVIS 5571 Mounting And Operating Instructions page 22

Communication
Modem
4
Modem = On:
PLC connected to telecommunications network over a modem (RS-232 Modbus slave in-
terface)
4
Modem = Off:
PLC directly connected to a computer (RS-232 Modbus slave interface) and on operating
the PLC in combination with cable converters (RS-232/RS-485)
Cyclical initialization
This parameter defines the period of time for a cyclical issue of the initialization command
"ATZ". The command is not issued during dial-up or when connected.
Automatic disconnection
When the controller connects to the building control station but without addressing a Modbus
data point, the PLC closes the connection after the time specified for Automatic disconnection
has elapsed.
Gateway
4
Gateway = On:
Any polling by the building control station to the Modbus instruments connected to the
PLC is passed directly on to the slaves.
4
Gateway = Off:
Any polling by the building control station to the Modbus instruments connected to the
PLC is not passed directly on to the slaves.
Frame
4
Frame = On:
4
Frame = Off:
Bias voltage
We recommend applying a bias voltage on the bus to keep the signal level stable. This bias volt-
age is usually applied to the bus by the Modbus master.
4
Bias voltage = On:
4
Bias voltage = Off:
22
EB 5571 EN
Framing function activated
Framing function deactivated
Bias voltage on the bus
No bias voltage on the bus