Rockwell Automation Publication 1756-RM003N-EN-P - October 2011 587
ASCII Serial Port Instructions (ABL, ACB, ACL, AHL, ARD, ARL, AWA, AWT) Chapter 17
Description: The AHL instruction can do the following:
· Obtain the status of the control lines of the serial port
· Turn on or off the data terminal ready (DTR) signal
· Turn on or off the request to send signal (RTS)
Follow these guidelines to program the AHL instruction.
1. Configure the serial port of the controller.
2. Use the following table to select the correct values for the ANDMask and
ORMask operands.
If your application Then
Uses ARD or ARL instructions Select User mode
Does not use ARD or ARL instructions Select either System or User mode
To turn DTR And turn RTS Enter this
ANDMask value
And enter this
ORMask value
Off Off 3 0
On 1 2
Unchanged 1 0
On Off 2 1
On 0 3
Unchanged 0 1
Unchanged Off 2 0
On 0 2
Unchanged 0 0
To Next Page
Loading...
Need help?
General
