Floating Points in RS Logix 500


Thread Starter

Mike Lynch

Has anyone had any practical experience with Floating Point data files in RS Logix 500 (release software. Currently attempts to include any instruction with a Floating Point value in older SLC 5/03 processors, brings
up an error message when the rung is verified. Data file 8 which is normally a F8 Floating Point file is found to be listed as 'reserved' (r8),
similar to a SLC 50/1 or 5/02, which is fixed.
This problem is not found on our newer 5/03 processors. Help files state floating points can be used on OS301 & OS302 processor operating systems. We have OS302's, but still some have this above problem.

Regards, Mike Lynch
Dairy Containers Ltd
Check the part number on the left hand side of the processor module. It should also tell you what the operating system software is that is in the module. You have to pull the module out of the rack to do this.

Dave Pryor
[email protected]

Gerald A. Groff Jr.

Yes I have seen this problem. The program downloaded in the 5/03 OS302 was configured for a 5/03 OS300. To solve the problem I changed the 5/03 OS version using the Controllers Properties. The re-configuration was performed off-line and then downloaded into the CPU.

Good Luck

Jerry Groff
ProFlow Inc.

Eric M. Klintworth

It sounds like the processor is defined as an OS300, which did not support floating point. Look at the processor type on the Controller
Properties "General" tab. You can change it to the correct processor type, or better yet, connect to the processor and read from it.
Uploading the program from the processor will also read the processor type, OS, etc.

That should take care of it. E-mail back if it doesn't.

Eric M. Klintworth, P.E.
Columbus, Ohio USA
Hi Mike,

It's easy to upgrade the SLC5/03 firmware to the OS302 level. A-B supplies a module that fits in the EEPROM socket and autoloads into the


Tom Rhodes
Pyxis Engineering Corp.