Rockwell Automation DAG6.5.8 APPLICATION GUIDE SCADA SYSTEM - Manual (Page 310)

Publication AG-UM008C-EN-P - February 2005
9-4 Configuring RSLinx Classic Software for DF1 Half-Duplex Communications
Figure 9.3 Port Configuration
Table 9.3 Port Configuration Parameter Descriptions
Control Control Text
COM Port Select the serial port of the computer from which the polling master driver communicates. The default is
COM 1.
Baud Rate Select the baud rate of the device with which the polling master driver communicates. The default is
19200.
Stop Bits Select the Stop Bits (1 or 2). The default is 1.
Data Bits Select the Data Bits (7 or 8). The default is 8.
Parity Select the parity of the device with which the polling master driver communicates. The default is none.
Use RTS Line In Windows NT only, if enabled, RTS is turned on when the polling master driver is about to begin a
transmission, and turned off when the transmission is complete. This behavior may change based on the
Hardware Handshaking timer values. If cleared, RTS is asserted (turned on) when the port is opened, and
remains asserted until the driver is terminated. The default is unchecked.
Delay before asserting RTS
(ms) This is useful when using half-duplex modems that require an off-delay timer to control the carrier wave.
When the driver receives characters, it may assert the RTS line to begin its own transmissions before the
sending slave has the opportunity to deassert the RTS line. This provides a minimum time delay between
when the driver determines it needs to transmit something, and the time it actually asserts the RTS line.
The default is 0.
Delay after RTS asserted &
before Xmit (ms) Some modems require a period of time after the RTS line is asserted for the carrier wave to stabilize. The
character transmission is delayed for the period of time specified. These values may be expressed in
milliseconds, but RSLinx Classic actually rounds the value down to the nearest 10 milliseconds. The
default is 50 ms.
Delay after Xmit before
de-asserting RTS (ms) Some modems require an off-delay after the last character is transmitted out the serial port before the
RTS line is deasserted. These values may be expressed in milliseconds, but RSLinx Classic actually rounds
the value down to the nearest 10 milliseconds. The default is 0.
Use CTS Line If enabled, characters are not transmitted out the serial port unless the CTS line is asserted. Not currently
implemented.