Drum counter? on FX1N

[tmechanic 0]

Does Mitsu have something equivalent to the drum counter used in OMRON?

[Sergei Troizky 26]

Yes, the absolute drum ABSD and the incremental drum INCD. Both control up to 64 consecutive bits (or outputs) in response to the assigned 16-bit counter absolute value (ABSD) or count since the previous switching (INCD). High-speed counters cannot be assigned to these instructions. Each of them may be used only once in a program. Edited 6 Jan 2006 by Sergei Troizky

[panic mode 246]

i have to support variety of platforms so i try to avoid instructions that are unique to one platform. any sequencer logic on mitsubishi I do with INC(rement)instruction when current step is complete. to do check, you have to decode step counter (D0 for example) to array bit. This is done with DECO instruction. And if you needto do jumping or looping just use MOV instruction. That's it.... And you can create as many sequencers as you like...

[Sergei Troizky 26]

I agree with Panic Mode. Also, sequencers are more difficult for program understanding and debugging. Some customers directly forbid use of sequencers in their specs. Edited 6 Jan 2006 by Sergei Troizky

[tmechanic 0]

Actually the drum counter already exists, customer has a bender with an Omron C28K and one just bit the big one so my company, we support the old Western Benders, wants me to rewrite this program to run on an available PLC. Since we carry and support Mitsubishi that's what they want to program to. And most of the opperations controlled by the sequencer would normally require a sensor input, but there are very few sensors on the machine. Edited 5 Jan 2006 by tmechanic

[tmechanic 0]

Oh yeah, the counts are different depending on wheather the bend option is on or off. it changes the count by about 11 depending on the operation.

[tmechanic 0]

Well the manual is clear as mud on ABSD, is S1 where it's getting it's initial count value? if so where does it get the end count? and in D, if I M0 in there out puts are M0,M1,M2, etc? and n is the total number of step? so K16 will give me M0-M15? Am I following this right?

[Sergei Troizky 26]

Ok, I never use drums myself, but I looked the manual carefully and see that I described the ABSD operation wrongly (now corrected). Actually, n consecutive bits starting from D will be controlled by the ABSD in responce to S2 counter value. For each bit, in consecutive order, you define the On target and the Off target. The targets table starts from S1. Yes, n=K16 and D=M0 will result in M0 to M15 being controlled. The source counter is not controlled by this instruction. Its reset, counting conditions and set value must be programmed separately. Edited 6 Jan 2006 by Sergei Troizky

[tmechanic 0]

OK, got it thanks.