GE 90-30 Mystery Analog Input???

Hello,

My GE experience is limited so please advise.

I'm working on a converting a GE 90-30 program over to ML1400 (1766-L32BXBA) for a Rod Coater.

During the process I ran into a rung that contained an analog value "AI0006" that I have no idea where it's getting the data.

The only analog input that the machine receive is a 1200PPR encoder signal and is addressed at "AI0002" - [Counter 1, continuous, Up, and the on preset and high limits at 1200].

When the encoder is turning, "AI0002" provides the pulse per second according to the 1000ms interrupt. "AI00006" on the other hand provides the actual pulse and rolls over at what seems to be 1200.

When referencing AI0006, it only appears in one rung and nowhere else. Please see attached image. Can the GE experts provide me with an insight? Thanks.

K

kay_gsr13 said:

During the process I ran into a rung that contained an analog value "AI0006" that I have no idea where it's getting the data.

Click to expand...

It should be getting it from an analog input module. Have you taken a look at the IO configuration?

All of the data from the high speed counter module comes into the PLC as fifteen words of %AI memory. The meaning of each of those fifteen words depends on the configuration of the counter. From your description, the counter is configured as Type A which means it has four independent 16-bit up/down counters. In that configuration %AI001 is the module status word, %AI002 - %AI005 are the count frequencies for the four counters. %AI006 - %AI009 are accumulated counts for the four counters. The maximum count and rollover action is set in the hardware configuration for each counter. The manual for the 90-30 high speed counter module is GFK-0293.

Steve Bailey said:

All of the data from the high speed counter module comes into the PLC as fifteen words of %AI memory. The meaning of each of those fifteen words depends on the configuration of the counter. From your description, the counter is configured as Type A which means it has four independent 16-bit up/down counters. In that configuration %AI001 is the module status word, %AI002 - %AI005 are the count frequencies for the four counters. %AI006 - %AI009 are accumulated counts for the four counters. The maximum count and rollover action is set in the hardware configuration for each counter. The manual for the 90-30 high speed counter module is GFK-0293.

Click to expand...

Steve,

You are correct, the HSC is configured as Type A counter and your explanation of the internal working and configuration of the GE HSC module was exactly what I needed. I had suspected that AI006 was the actual accumulated pulse from my encoder pulse, thank you again for the confirmation.

K