High Speed Counter On Micrologix 1500

[lostpatrol1]

Hello,
I am running a Micrologic 1500PLC (has 2 high speed counters) and I am using the HSC1 function.

How do I specify which input (4-7) to use for the HSC1? Right now it works on input #4 (which I believe it is the default), but I want to use it on other input other than #4.

Thanks.

 

[PhilipW]

The HSC counters are small hardware subsystems that run independently of the logic program.

For this reason their inputs are "hard wired to predefined I/O terminals and cannot be altered by the program.

I am sure that AB could make them reallocatable if it was necessary, but on such small systems it hardly seems necessary.

BTW if an HSC inputs are always addressable by the logic program, even when the HSC is counter is using them.

 

[Ken Roach]

The first high-speed counter subsystem on a MicroLogix 1500 is connected to Inputs 0-3 (A,B,Z,Reset) and the second high-speed counter subsystem is connected to Inputs 4-7 (A,B,Z,Reset).

As PhilipW said, these input points are wired directly to the high-speed counter circuitry, so they can't be configured to run with other inputs on the device.

So, whatever you have using Input 4, you'll have to move to another input terminal.