Parameter
Supported Values
Data Bits
7 or 8 Bits
Default: 8 Bits
Stop Bits
1 Bit
Default: 1 Bit
Receive Flow Control
None or Xon/Xoff
Default: None
Transmit Flow Control
None or Xon/Xoff
Default: None
Station
1 to 65534
Default: 1
Protocol
None, Modbus RTU or Modbus ASCII, DF1 or DNP.
Default: Modbus RTU
Addressing Mode
Standard or Extended
Default: Standard
COM2 transmits and receives differential voltages to other RS-485 devices on a network. The RS-
485 specification allows a maximum of 32 devices connected on a single RS-485 network. The
specification for RS-485 recommends that the cable length should not exceed a maximum of 4000
feet or 1200 meters.
The signal grounds of the RS-485 devices in the network are not connected together but instead are
referenced to their respective incoming electrical grounds. The grounds of the RS-485 devices on the
network must be within several volts of each other. Controller ground is connected to the chassis.
SCADAPack 350 Hardware Manual
February 14, 2007
39
