WindLDR timers

[Bolt]

Hello there. New guy here. I am writing my second program in WindLDR. A considerable portion of this program needs to run off of time. Example, once the portion of the program is initiated, output 1 comes on at 5 seconds, goes off at 35, input 2 comes on at 10 seconds, and lasts until 50, etc. What is an easy way to program this? The timers I have messed with in WindLDR are all counting down, meaning they have an set value to start with. What I would like is a timer that counts UP when the start signal is pressed, and then the rest of the signals are triggered by the time being <,>,= to the timer and so on. A countdown timer would be a big pain to tweak the settings later, as the numbers would have little meaning, and if the overall cycle time would need to be adjusted, all the other values would change. Or do I just need to set my timer high (1000 or 10,000 seconds maybe) and then do math functions to get it to a counting up number to use in triggering my outputs? Ex.
D0001=(1000-T001) SET Q0001
D0002=(1000-T001) RST Q0001

This is going to run on MicroSmart 24's, I have both the Pentra and the older version of the PLC that I need to have a similar type of program on.
Is there something I am missing as far as making this easier? I am just trying to make it as simple as possible, as it will be a fairly large program by the time I am done.

Thanks!

 

[Jon R]

Is time accuracy critical? If not you could use internal clock pulses to do your time function with a counter albeit the accuracy may not be top notch due to scan times and processing time for instructions.

Idec uses 3 separate internal relays. M8121 is a 1s clock function, M8122 is a 100ms clock function and M8123 is a 10ms clock function. Combine these with a CNT counter and then just do a compare >= to the values you are looking for and trigger an internal relay.

If in doubt read the manual, or download it from Idec's website for free.


Jon.

 

[Bolt]

When you say critical, how precise is the clock counter? Most of the times are not critical, +/- a second would be just fine. A few of the times would be nice to be exact each time, each day, but I could always use a countdown timer on those. I'll read some more in the manual, and see what I come up with. Have spent quite a bit of time in it, but not always reading in the right places I guess. BTW, the MicroSmart's don't come with an internal clock, it's about a $35 option to add one later, I do have 1 clock on order, but not real sure on which PLC I am going to use it in yet.

 

[Jon R]

So are you looking to trigger things at certain times then. M8121, 8122 and 8123 are internal pulse relays that do not require the clock cartridge. They are accurate enough if you are looking at +/- sec. The 8121 is on for 500msec then off for 500msec, 8122 on for 50msec and off for 50msec etc.

 

[Bolt]

I read it as M8121 1 sec clock M8122 100 ms clock and 8123 10 ms clock.

So I could trigger M8121 to run my counter, and then use counter comparisons to start and end the outputs. That should do the trick for me.

 

[raviv]

Just Subtract The Curent Value From The Preset: Sub [s1=preset{constant}
S2=t000 D1=d0000] T0000 Is Yuor Timer And Use Data Register D0000 As Base To Compare.

Hope This Will Help.