Allen Bradley DF1 Serial Channel Tag


The Allen Bradley DF1 Serial Channel Tag Channel Tag Icon provides a DF1 serial SCADA/HMI communication channel to Allen Bradley PLCs.

Configuration Properties

The Allen Bradley DF1 Serial Channel Tag supports the properties of the Allen Bradley Channel Tag plus these properties:

Property Type Version Description
Mode WSTRING 2.2 The serial port communication speed, data format and handshake mode.
Click the Browse button Browse button to edit the serial port mode using the Serial Port Mode Editor. You can also type in the serial port mode string directly. See Serial Port Mode String for how this property is formatted.
Port WSTRING 2.2 The name of the communications port. For example 'COM1:'
ErrorCheck USINT 2.2 The error checking mode.
0 = CRC, 1 = BCC.
Protocol USINT 3.8 The protocol variant used by the channel.
0 = Full Duplex, 1 = Half Duplex.
SourceNode USINT 2.2 The node address used on this channel by Fernhill SCADA (0-254).
TransmitDelay TIME 3.8 Only used in Half Duplex mode. The delay between the start of the next transmission and the last character received.
Note: If you are using a 1761-NET-AIC+ Advanced Interface Converter between Fernhill SCADA and the PLC, use the default value of 20ms to ensure the Auto Transmit Delay feature of the interface converter does not drop the start of the transmission from Fernhill SCADA to the PLC.

Tag Commands

The Allen Bradley DF1 Serial Channel Tag supports the tag commands of the Allen Bradley Channel Tag.

Example Configuration

This is an example of a channel configured to support an Allen Bradley PLC Tag via COM1 using DF1 Full Duplex mode at the default communication settings of 19200 Baud, No Parity, 8 Data Bits and 1 Stop bit:

ModeBaud=19200 Parity=N Data=8 Stop=1
ProtocolFull Duplex

Relationships to Other Tag Types

The Allen Bradley DF1 Serial Channel Tag builds on the features of these tag types:

Further Information

Allen Bradley PLC Tag

To learn about the Allen Bradley PLC Tags that can be associated with Allen Bradley DF1 Serial Channel Tags.

Alarm Handling

To learn about alarm management.

Serial Port Mode Editor

To learn how to set the communications speed, data format, and handshake mode of the serial port.


For definitions of the terms used in Fernhill SCADA.