allen bradley slc500

HI everyone I've got a lot of experience on programing Siemens plc like S5 or S7 200 but not clue when it comes to ab slc 500 somebody can give me some hint's or tips. I'm pretty sure that the ladder logic should be similar .
How I can transfer my s5 or s7 program to ab slc 500


thanks in advance

1. No "reusable code" in SLC500.
SLC500 doesnt have the reusable code system that S5/S7 have.
The closest thing is that you can pass some words back and forth when calling a subroutine. But you will have a tough time if you want to port S7 FBs with instance DBs to SLC500.
SLC500 is really a "classical" way of doing PLC programs.

2. SLC500 is ladder diagrams only.
If you can switch your S5/S7 code to LAD, then you are in luck.
SLC500 ladder code is very similar.
On the other hand, if you have a lot of S5/S7 STL code, it will be tough going.

3. S5 timers and the S5Timers in S7 are very different from the timers in SLC500. In S5/S7 the timer counts down to zero, in SLC500 the timers counts up from zero. The setpoint and the actual value is two separate adresses (ex: T4:0.pre and T4:0.acc). You investigate if a timer is TRUE with the "done" bit (ex: T4:0.dn).

4. VERY IMPORTANT TIP #1:
Examine the "math overflow" bit (S:5/0) at the end of the program scan, and if set make an alarm on the HMI, AND then reset the bit. If not the PLC will fault. (All newcomers to SLC500 will sooner or later experience that the CPU faults for this reason. And if you are not prepared for it, it will happen at the worst time).

5. VERY IMPORTANT TIP #2:
If you use an EPROM (recommended), then set the bit "Load memory module on memory error" (S:1/10). Store the program to the memory module with the bit set, otherwise the CPU will fault.

6. There is no error program file system like the OBs in S5/S7. You must investigate the error bits in the status file if you need such functionality.

7. Learn the SLC500 instruction mnemonics (ex. XIC for a N.O. contact). Editing the instructions with the keyboard is much faster than using the mouse.

thats what I could come up with off the top of my head

I would suggest getting the manuals for the instruction set and the hardware you will be using. http://www.ab.com/manuals/
Instruction Set manual for SLC500: http://www.ab.com/manuals/cp/1747-rm001d-en-p.pdf

I will mention that the SLC500 has 2 Timer instructions
TON Timer On-Delay
Use the TON instruction to turn an output on or off after the timer has been on for a preset time interval. This output instruction begins timing (at either one second or one hundredth of a second intervals) when its rung goes "true." It waits the specified amount of time (as set in the PRESET), keeps track of the accumulated intervals which have occurred (ACCUM), and sets the DN (done) bit when the ACCUM (accumulated) time equals the PRESET time.

As long as rung conditions remain true, the timer adjusts its accumulated value (ACC) each evaluation until it reaches the preset value (PRE). The accumulated value is reset when rung conditions go false, regardless of whether the timer has timed out.

Instruction bits: 13 = DN (done)
14 = TT (timer timing bit)
15 = EN (enable bit)

If power is lost while a TON is timing but has not reached its preset value, the EN, and TT bits remain set , and the accumulated value (ACCUM) remains the same. This is also true if the processor changes from the REM Run or REM Test mode to the REM Program mode.

If either the Accumulator or the Preset is negative when the TON instruction is executed on a true rung, a Major Fault (0034) is generated.

TOF Time off-delay
Use the TOF instruction to turn an output on or off after its rung has been off for a preset time interval. The TOF instruction begins to count timebase intervals when the rung makes a true-to-false transition. As long as rung conditions remain false, the timer increments its accumulated value (ACC) each scan until it reaches the preset value (PRE).

The Accumulated value is reset when rung conditions go true regardless of whether the timer has timed out.

slc 500

Hey guys thanks a lot for yours tips , I've got already the set of instruction from ab.com/manuals & thanks for the explanation about the timers and all that .


thanks again