User manual
IEC61131 User and Reference Manual 
April 22, 2008     
114 
The Store and Forward drop down menu selects whether store and forward messaging is 
enabled for the port. Valid selections are enabled and disabled. If this option is enabled, 
messages will be forwarded according to the settings in the store and forward routing table. 
The default selection is disabled. This control is disabled when PPP protocol is selected for a 
serial port, or if any of the DF1 protocols are selected and for com 1 on the SCADASense 
series of programmable controllers. 
The Store and Forward menu selection changes to Routing menu selection when DNP 
protocol is selected for a serial port. Valid selections are enabled and disabled. Routing must 
be enabled on a serial port to enable routing of DNP messages. 
The Enron Modbus drop down menu selects whether Enron Modbus is enabled for the port. 
If this option is enabled, the controller, in addition to regular Modbus messages, will handle 
Enron Modbus messages. Valid selections depend on the protocol as shown in the table 
below. This control is disabled when PPP protocol is selected for a serial port and for com 1 
on the SCADASense series of programmable controllers. 
Protocol 
Valid Selections 
Default Selection 
Modbus RTU 
Modbus ASCII 
Enabled 
Disabled 
Disabled 
DF1 Full Duplex BCC 
DF1 Full Duplex CRC 
DF1 Half Duplex BCC 
DF1 Half Duplex CRC 
Control is disabled 
N/A 
DNP 
Control is disabled 
N/A 
None 
Control is disabled 
N/A 
The Enron Station entry selects the Enron Modbus station address for the serial port. Valid 
entries depend on the protocol. The Enron station must be different from the Modbus station 
set in the Station control. This ensures Enron Modbus and Modbus communication can 
occur on the same port. This entry is greyed out if Enron Modbus is not enabled. 
Protocol 
Valid Values 
Default Value 
Modbus RTU 
Modbus ASCII 
Standard addressing: 
1 to 255 
Extended addressing: 
1 to 65534 
2 
DF1 Full Duplex BCC 
DF1 Full Duplex CRC 
DF1 Half Duplex BCC 
DF1 Half Duplex CRC 
Control is disabled 
N/A 
DNP 
Control is disabled 
N/A 
None 
Control is disabled 
N/A 
The OK button saves the settings for all serial ports and closes the dialog. 
The Cancel button closes the dialog without saving. 
The Default button sets the parameters for the port to their default values. 










