BIGEYE

I'm in a bit of a problem. Something has gone wrong with my old comms card, and it looks like I need to reinstall the driver. I am having a real problem trying to locate the driver, so if anyone can point me to a download, or send it to me, I'd really appreciate it. I'm looking for a 1784 PCMK/B comms card driver for Windows XP Pro.

Thanks for that.

We have a number of SLC5/04 PLC's networked over DH+. If I have a digital input to say PLC 1, how could I network this and pick it up as an output on PLC 3.

Thanks, not too familiar with message instructions.

Fitted plates to the filter arms so that the proximity switches have a larger target and provide a longer pulse, also to reduce the likelihood of two or more quick pulses. Also modified the code as chelton suggested. The changes have been working now for about ten days, so I think we can say that our problem has been resolved. Thanks to all that have helped, especially to cbuysse, OkiePC and chelton.

I am new to PLC's and request some help with some code I need to write. I have a rotating irrigation arm on a bridge with a proximity switch that detects a pulse each time an arm passes, the bridge has two arms, therefore sees two pulses per revolution. I need to monitor the revolutions per minute or hour, and displey the RPM or RPH on an HMI. The PLC ia an SB SLC5/04 and the HMI is a Red Lion Controls VX5000. My thoughts are to count the pulses over a minute or hour period, then divide this total by 2. The result is displayed on the HMI. The start the next count and then update the HMI with the result. Can anyone comment on my thoughts and advise if there is a better way to acheive this. Also advise how I should write this code. TIA

There is a possibility that this may be happening. I am getting plates made so that the proximity switch has a bigger target. These will be fitted next week hopefully.

Thanks Scott for the reply. Rung 51 does not form part of my code. The code is from Rung 53 to the End instruction.

I won't get back to this site until next week, I'll have a tinker then. ATM I have disabled all the rungs for the rev counters just in case something else is causing the problem.

Also attached is a screenshot of the status during the plc error.

Well here goes with my code, I hope it makes sense. I have 3 tanks with a rotation monitor on each tank. Rungs 53 to 59 are for Tank 1. Rungs 60 to 66 are for Tank 2. Rungs 67 to 73 are for Tank 3. Input I:4/12 is the Pulse input from the proximity switch on Tank 1 Input I:5/9 is the Pulse input from the proximity switch on Tank 2 Input I:6/10 is the Pulse input from the proximity switch on Tank 3 So basically the code is identical code for each Tank, only different addresses. Description Rung 53 has Timer T4:16 which times up. Rung 54 has the proximity switch pulse input for Tank 1. The tank sees 1 pulse per Rev. When it sees the pulse, the OSR B3:0/6 is triggered. This in turn moves the accumulated time from T4:16 to N16:44. It also resets Timer T4:16 back to 0, which then starts timing again until the next pulse from the proximity switch. Rung 55 has the NEQ block, so that when N16:44 is not equal to 0, then the maths are performed. The DIV block divides 600 by the accumulated time that was moved in to N16:44. This effectively gives me RPM to 1 decimal place. For example, if I had an accumulated time of 50 secs, the maths would be 600/50 = 12, our HMI is set to 1 decimal place so this reads as 1.2 RPM. The result is put into N16:45. The MUL block multiples whatever is in N16:45 to give me revs per hour (RPH). The result is put into N16:7 Rung 56 Has CTU C23:4 which counts the pulse passing the Proximity switch. C23:4 has a Preset of 1, because we now only have 1 pulse per rev. When the proximity switch sends the pulse, it resets C23:4, which then sites at 0 until the next pulse. Rung 57 has C23:4/DN, when this triggers by what happens in Rung 56, it causes C23:5 to increment by 1. This also moves 0 back in to C23:4 to reset the accumulated total to 0. Rung 58 When the S40 clock equals 9 hrs, OSR B3:0/11 is triggered and moves C23:5.ACC into N16:61. This is my count of Revs over the last 24 hrs. This also moves 0 back into C23:5.ACC thereby resetting the accumulated total back to 0. Rung 59 moves C23:5.ACC total to N16:63. This gives me a running total of revs. The other rungs do exactly the same for the other tanks, only different addresses. EAST CALDER RTU2 31-12-12 REVIS.pdf

The one shots are unique, not used elsewhere. I will upload a PDF of the code when I get home tonight. Thanks

Since adding this code, the plc has failed twice. My colleague went to it last time and found the plc to have an S5 fault. He reset this fault ant it went straight back in to fault. He then removed the code and was able to rest the S5 fault. He then put the code back in and it has been working fine for a few days. It has failed again today, and I will attend later. I can only assume that the plc has failed on the same fault. Any ideas?

The changes work just fine, thank you very much for that. Can I ask what you are using as an amulator?

I have done the code like this, but it seems to have a couple of errors. Counter1 was not counting as it was continually being reset by the XIO and RES counter 1 in rung 2. I changed the XIO in rung 2 to an XIC. Counter 1 is now counting. Also, when the total is being rest, the accumulated total in the counter starts at 1 instead of 0, therefore it only needs to see another 3 pulses before resetting again. As a workaround, I have made the preset of counter1 set to 5.

Thanks, will let you know how I get on on Monday.

Thanks for that, the proximity switch picks up the arms of a filter. If you thnk of the letter X revolving about a pivot in the centre, the proximity switch picks up each leg as it passes, hence 4 pulses per rev. It rotates at about 1.4 RPM on average, so would pick up about 8064 pulses over a 24hr period.

Our ops people are well pleased with the rev counter, and now want to go one step further. Ops now want a display of the number of revs over a 24hr period. So for example, the 24hr period starts at 08:00 hrs and pulses start to accumulate from then, at the end of the 24hr period, the total is dispalyed. Another 24hr count period is started, at the end of which, the new total overwrites the old total and a new count period starts. The process is then repeated. I have wrote some code which has errors, and it looks cumbersome. I will be going back to site on Monday to try and sort it out. What would be the best way to write the code to acheive the objective? THA

Excellent, working like a charm. Thanks for all the help.

Got it working by adding the second timer contact, have left site for today and will be revisiting tomorrow so will see how it is working, and will report back. Thanks guys for the help.

That doesn't work, what I have already is 4 rungs of code as follows: Rung 1 Digital input I:4.0/12 XIC to a count up counter C23:4 with a preset of 32000 Rung 2 MOV instruction to move C23:4.ACC to Dest N16:6 Rung 3 DIV Source A N16:6 by Source B which is 4, Dest is N16:7 Rung 4 Time pulse XIC pulses once every hour, which resets counter RES C23:4

The pulses are slow, I get about 4 pulses per rev, with each pulse about 1 second. I am able to count the pulses over a time period, this total is then divided by 4 to give me revs per minute or hour depending on the time period i choose ( either minute or hour depending on what is most suitable. At the end of my time period, my counter is reset and the count darts again for the next time period. What I am struggling with is the total, I need this to be held somewhere and also displayed on the him. Unfortunately, the total resets to 0 when the counter resets. In reality, the displayed total should indicate rpm or rph and not change unless the revs actually change. So all I am looking for is a revs per minute or revs per hour display. Hope this makes sense, or am I doing things the hard way. Is there a better way?

I have a spare analogue output on an SLC 5/04 and a digital input. I want to output 12 mA from the analogue output when the digital input = 1, and output 4 mA when the digital input = 0. What would be the way to do this? TIA

I have an SLC 5/04 going in to fault and cannot find the cause. The error description reads: A minor eror bit is set at the end of the scan. refer to S:5 minor error bits. When I reset the fault and switch back to RUN, the plc goes in to fault immediately. The only way I can get the PLC operational is to download a backup of the PLC code to the PLC. However, after a couple of days, the same fault comes back again. The column of boxes at the left shows a 1 in only the Major Error Halt S:1/13 if this is of any significance. Appreciate any help on this one. TIA