Modicon to AB
Modicon to AB
(OP)
I have been given the tedious task of converting an old 484 Modicon program to a new AB SLC5/03, and have never touch a Modicon before. Is there any programs for converting the programs? or do I just do it line by line. And are they any pit falls I should watch out for?
Regards
Regards





RE: Modicon to AB
I can't recall if the 484 had the network-vs-rung structure, but if it does, keep in mind that the 7x11 network solves vertically first (solves the first column, then the second column, etc.), regardless of rung structure. This can really kick you in the backside if you are not aware of it.
-Brad
RE: Modicon to AB
RE: Modicon to AB
RE: Modicon to AB
However i would say you 2100 address are coming from an HMI...With modicon they use an output adress for an input from an HMI...(Sounds confusing dont it!!) This takes a while to get your head around...But if you have the instructions and no in/out that seems relivant then that is what i would put my money on..
RE: Modicon to AB
Be aware that some instructions may actually use more registers than is shown on the function block. Many math functions will use a set of contiguous (i.e.: 42100, and 42101) registers, but that's more of a concern when developing for that PLC, UNLESS--the implied register is used by logic elsewhere, which would contribute to the mystery of "where's this number coming from?" In short, you would benefit from a manual describing each function block and it's register usage. Unfortunately, I have no experience with modicons older than the 984 series so I can't help with specifics--though yours MAY be the same as 984s and later.
To get a book, goto www.modicon.com, click on search (very small in the upper left area of page) and search for 840USE10100. The first result returned should be "Modicon Ladder Logic Block Library". You can download a PDF of the book from there.
RE: Modicon to AB
As one of the previous posters noted, one of the big differences between AB and Modicon is scanning top to bottom vs left to right. It can get you if you're not careful. Another big difference is the (L) coils. In Modicon these are not really latching coils like they are in AB. Modicon really doesn't have the equivilent to (L) and (U). In Modicon the (L) coil tells the processor to save the state of the bit on power down and turn it back on at power up.