SLC 5/04 timebase

Does anyone know why Logix 500 won't let me use timebases of 0.001 seconds with a 1747-L552B 5/05 processor? I can't seem to find anything in help about it, the AB Knowledge Base, or the instruction manual.

I know this looks like a stupid question; but I just got done with a project with a MLX1500 and had to use this timebase. Worked with no problems. Why the difference?

Thanks in advance.

Sportster

The MicroLogix 1500 is actually the fastest SLC-family CPU. The 1 millisecond timebase was implemented only in the MicroLogix 1200 and 1500.

RSLogix 500 software knows that 1 ms is an invalid timebase for timers in SLC modular controllers, so that's why you get the error.

Heres the Knowledgebase article.

That makes sense Ken. I guess I thought that since I could use it in the 1500; it should work in the 5/05 as well.

Thanks again!

Sportster

I knew they were lying to me!

I am currently doing a comparison of PLC products for our company. I contacted the distributor who said the timebase for the SLC 5/05 was 1us. I thought this was strange since it was the ONLY controller of all 4 systems I was investigating that had the 1us timebase. I called AB tech support, who said it was 10ms, and then said, "Well what did the distributor tell you?" I said, "1us." He said,” That is correct."

AB - Liars. They tell you want you want to hear.

Thanks for asking the question.

Careful throwing "liars" around. Perhaps the question asked to tech support was the problem.


There is a 10ms timer timebase
There is a 1ms timer timebase (Micro 1200 and 1500 only)
There is a 1ms Selectable Timed Interrupt
There is a 10us Timestamp
There is a 100us Discrete Interrupt.

Perhaps ellisma0607 if you want to reply with your case # from Tech Support I can find out for you why you got the answer that you did.

There is no point in lying to you about this when all you had to do was go check the manuals on the website which spell it out clearly.

OG

ellisma0607 said:

I am currently doing a comparison of PLC products for our company. I contacted the distributor who said the timebase for the SLC 5/05 was 1us. I thought this was strange since it was the ONLY controller of all 4 systems I was investigating that had the 1us timebase. I called AB tech support, who said it was 10ms, and then said, "Well what did the distributor tell you?" I said, "1us." He said,” That is correct."

AB - Liars. They tell you want you want to hear.

Thanks for asking the question.

Click to expand...

I'd say its more likely that he misunderstood or misspoke.

ControlLogix controllers use a .001 second timebase (32 bit)
MicroLogix controllers support .001, .01, 1.0 second timebases.
PLC5 and SLCs (aging legacy platforms) support .01 and 1.0 time bases.
PLC2 (really old legacy) has a .01, .1 and 1.0 time base in BCD.
SLC100/150 (really old but still thousand around) has only a 0.1 time base.