How do I perform forward/reverse with only a single polarity speed reference?
There are many ways to do this within the PL/X but our preferred method is always to perform any sequencing external to the drive if practicable as doing so keeps as many drives as possible in default configuration. In this instance, as a contact would have to be used to tell the PL/X to reverse this contact may as well be used to switch the top of the setpoint pot (if used) between + and - 10V. If an external speed reference is being used the method is to switch the signal between two speed demand inputs and set the scaler of one of them to -1.0000. However, if it is necessary to use a digital input for the purpose - perhaps because that is how it was done on previous occasions with other drives, one solution is as follows (assuming that DIP1 is being used for the switching and that UIP4 is used for the speed demand input):
Go to CONFIGURATION, ENABLE GOTO,GETFROM and set to ENABLED.
Go to CONFIGURATION, DIP1 (T14) SETUP, 310) DIP1 IP HI VALUE and set it to -100.00%
Go to CONFIGURATION, DIP1 (T14) SETUP, 311) DIP1 IP LO VALUE and set it to 100.00%
Go to CONFIGURATION, DIP1 (T14) SETUP and set its GOTO to 342)UIP4 CAL RATIO.
Go to CONFIGURATION, ENABLE GOTO,GETFROM and set to DISABLED.
Don't forget to do a PARAMETER SAVE once you have finished, and please also see a later note regarding parameter unit values for an explanation of how the PL/X treats numbers.