Changing from a Hitachi to IDEC PLC

Good Afternoon all.

Our (ancient) Hitachi PLC on a reverse osmosis plant is dying and my Boss wants to use an IDEC MicroSmart PLC to replace it. I have very limited exposure to PLCs, but the ladder looks very simple, and I have managed to convert most of the I/O, internal relays etc over to IDEC. I am a bit confused about the counters and timers though - the counters have two inputs, the top one looks like the "pulse" for the counter to count down, whilst the second input looks like a reset - does that sound correct (opposite to IDEC)
The timers look similar with just a single input.
Also, does the IDEC have a one minute clock pulse relay
Any help would be appreciated - enjoy your weekend!

Regards,

Wayne

OK, the way your question is written, I'm not abolutely sure if you're asking about the IDEC counters and timers or the "Hitachi".

bigvicfella said:

I am a bit confused about the counters and timers though.

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I would think you obtained a "user's manual" with your shiny new Microsmart, and can look up the configuration of the counters and timers for it. If not, let me know and I'll help all I can.

I'm not sure of the configuration of the Hitachi Cs & Ts but I have seen other brands with the counters configured as you say, the upper input is the "count" input and the lower input is the "reset" input, (opposite of IDEC).

bigvicfella said:

Also, does the IDEC have a one minute clock pulse relay

Click to expand...

As of the printing of MY users manual they did not. You have to make one with a counter preset to 60 and a 1second pulse (m8121). The counter only counts the leading edge of the pulse so you don't need a SOTU command. The reset input also only "resets" the counter when it changes form OFF to ON.

There is a NEW Microsmart coming out http://www.idec.com/usen/products/Catalogs/PLCs/MicroSmartPentra/overview.html
the "Pentra", and my rep has made all kinds of claims about it, including "a 1 minute clock".

Stationmaster

Wayne,

Not sure how Hitachi worked their counters, but Idec always have the first block input as reset or preset depending on which type of counter you are using. The timers are indeed single input only but rely on a constant connection for the timer to run to it's preset time.

If you need a copy of the manual in PDF they are available from the idec website www.idec.com or I can email you both the Microsmart and Pentra.

Stationmaster, the Pentra has been out for a while but having gone through the manual I can't see a one minute clock, just the standard M8121, 22 and 23.

Jon.

bigvicfella said:

Also, does the IDEC have a one minute clock pulse relay
Any help would be appreciated - enjoy your weekend!

Regards,

Wayne

Click to expand...

If your using the add on Clock cartridge then just fire a oneshot every time the minute value changes.

If you don't have the Clock then just use a TML Instruction set for 60. Have this fire a oneshot and at the same time reset the TML.

Jon R said:

Stationmaster, the Pentra has been out for a while but having gone through the manual I can't see a one minute clock, just the standard M8121, 22 and 23.

Jon.

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Yeah, I haven't had the pleasure yet........My IDEC rep is difficult to understand sometimes, and ALWAYS "thinks" the next model has whatever feature I'm asking about at the time. I keep getting info on the Pentra, but haven't talked to anyone who has actually used one yet. You?

Stationmaster

No have got one at work(FC5A-D16RK1) that I brought to use as a demo PLC with a touchscreen system, but haven't had the time to set it up yet and now using Telemec as main platforms anyway.

Jon.

Thanks everyone for your assistance - I hopefully have enough info to complete the task! VMT Stationmaster, JonR, BitsNBytes

Regards

Wayne

Stationmaster said:

Yeah, I haven't had the pleasure yet........My IDEC rep is difficult to understand sometimes, and ALWAYS "thinks" the next model has whatever feature I'm asking about at the time. I keep getting info on the Pentra, but haven't talked to anyone who has actually used one yet. You?

Stationmaster

Click to expand...

I put in an FC5A-C24R2 earlier this year. It replaced a similar FC4A, (non pentra) which I used for the fan/cooling control.

It is fast, but I have no way to test that, nor is it of any benefit to me right now. I am contemplating replacing the FC5A-C24R2 with a "slim" type CPU, along with some expansion cards. Partly for room, partly for a bit better performance, as I will be adding a bunch of stuff to this in the future, and I run some MOV commands that are quite large. The one used right now will get put on another project.

Microsmart Pentra (FC5A) Slim Style:

Basic contact instruction LOD 0.056 μs
Advanced instruction MOV 0.167 to 0.278 μs
Basic Instruction Execution Time/1000 steps 83 μs

Microsmart Pentra (FC5A) Brick Style:

Basic contact instruction LOD 0.7 μs
Advanced instruction MOV 33 μs

Microsmart (FC4A) not sure what style:

Basic contact instruction LOD 1.0 μs
Advanced instruction MOV 46 μs
Basic Instruction Execution Time/1000 steps 1650 μs

As you can see, quite a bit of performace difference. Similar numbers for memory space, number of data registers, etc.

Well Hello There Bolt,

How's the VFD upgrade mooooving along? (sorry)

: )

Sounds like the Pentra would have an advantage on large programs where scan time may become an issue......I'm TOLD it has a built in A/D input and some features that make it well suited to RS485 comms. Hard to sort out the hype from the actual.....guess I'll have to buy one.....

Stationmaster