View Full Version : Modicon A984-145

December 16th, 2010, 02:26 PM
Im trying to convert a Modicon to a Compactlogix. Its really hard to find anything on the Instruction set of the A984. So I hope someone here could help me. I only have a .txt document no program or software.

Im stuck on a EMTH instruction, I get that it is a Extended math but not sure what function it is. On the top segement 40062 is used = with a value of 19687d and 40063 value of 17157d. Middle seg. 40144 = 16908d. And bottom seg = #0022. Also there is lines coming off all three segements with outputs. Hope this is enough information.

December 16th, 2010, 02:47 PM
function block is just doing a compare that is what the #22 stands for

December 16th, 2010, 02:49 PM
thank you - do you know of a document that explains the # numbers there is other EMTH instructions in the program like a #0013 or #0020

December 16th, 2010, 04:48 PM
See link below


December 17th, 2010, 11:35 AM
I have found that manual before - but nowhere in there does it same #0022 is a compare funciton or #0013 is this function. Has stated before I dont have the programmning software just a paper printout.

After looking through the program its mostly just ladder execept for EMTH functions #0013 and #0020 and #0018.
If you could help me out with those that would help thanks.

December 27th, 2010, 12:16 PM
sorry for the bump but does anyone have an idea what function #0018 #0019 and #0020 are?

Jim Dungar
December 27th, 2010, 02:27 PM
An old Modicon 984LL resource
890-USE-146-00: primarily for the old Modicon Micro (110CPUxxxx) but the instruction set is also applicable to the 984 compact.

Extended math instructions begin on page 133.
Yours all deal with floating point math.

December 27th, 2010, 03:09 PM
thank you very much - exactly what I was looking for just could'nt find it on that thing they call a website.

Mike Lamond
December 27th, 2010, 03:41 PM
I thought I'd seen something with the function numbers, but it's been over 10 years since I worked with a Micro 984. In ProWorx 32, you can select function name or numeric display of EMTH function codes with the cryptically named checkbox "Multi Function Naming" on the Logic tab of the View Properties dialog box. Either way, the selection is only by function name. Obviously, this is no help with only a hardcopy listing.

Jim Dungar
December 27th, 2010, 05:32 PM
thank you very much - exactly what I was looking for just could'nt find it on that thing they call a website.

Here is the one written for the Compact controller - bulletin GM-A120 LDR.

For more information, try what I did:
Go to www.schneider-electric.com (http://www.schneider-electric.com) and search for "984 Compact".