Which PLC do I need?

[Guest Storm-O]

Hi all, I'm totally new to PLCs and wondered if you guys could guide meg alittle. The project I'm working on consists of 3 intelligent drives, which will be selfsupporting during normal operation. However, when connecting the system to a client system (typically a PC/PDA through bluetooth, which will upload firmware, alter operational parameters etc) I need more power. The requirements for the PLC: - Two RS232 ports (one for client connection, and one to the drives. Combining the two will create havoc) - Sin, Cos, and preferrably ArcSin & ArcCos functions - Fairly large memory (>16Kb) - GOOD environmental specs (-20C to +70C in high humidity) Any help would be greatly appreciated! Thanks! Storm-O

[KinK 0]

I have had the omron PLC's in the worst mining conditions you could imagine and have had very few failures not one cpu yet (knock on wood) you could try the CS1 or the CJ1 they will both do what u want and are relitively cost effective. Peace

[Guest Storm-O]

Just downloaded the operational manual, and all I can say is Wow! Suits me just perfect, and lucky me Omron here in Norway just happens to run an offer for the new CJ1M-CPUx1 products! Thanks for the info Kink! Storm-O Edited 17 Jul 2004 by Storm-O

[KinK 0]

Np if you need any specific help getting started there are some great tutorials in the download section and you can also always ask. Peace <>

[Guest rswolff001]

Stay with something SUPPORTABLE!!!! Any of the smaller units, i.e. Mitsubishi, Aromat, Fuji, PlcDirect, etc. will drive you crazy unless you have a lot of experience. Hardware cost should be of minimal impact as you will spend a lot of time and effort (costs money) resolving problems or attempting to figure out Japanese translated manuals. I would highly recommend Allen-Bradley in this case...probably a SLC5/03 with an additional basic module. Costs more for hardware and software but lots of good support available. You didn't mention why you need a plc? if all you have is serial I/O there are better alternatives. You said you're new to plc's...do you have any other programming experience? Basic? Pascal? C? If so, there are many single board computers which may offer better serial capabilities inside of an environment you're familiar with. bob

[Guest Storm-O]

Seems to me that PLC controls are slightly more reliable than SBC's, and usually can endure worse conditions. The conditions I'm putting the system into are pretty harsh, with high humidity and -20C to +70C. Yes, I'm new to PLCs, but not new to programming, and know C/C++, Java, and assembly, so the PLC language shouldn't be a big problem. However, do you have any suggestions for some good SBC that could the job within the environmental specs I mentioned above? Also, the equiment I'm interfacing agains has it's on CAN bus implementation, but also supports the DeviceNet protocol, which at least makes it easy to interface with the Omron CJ1, which KinK suggested above. Thanks for your input! Storm-O

[BobB 58]

The CJ1 is an awesome beast, if you go for the higher end processors. Does not require a backplane and has 64 bit input and output cards. About the size of a cigarette packet. My favourite PLC. CX-Protocol allows easy writing of protocols to serial devices and really makes life easy. You could do far worse that select this route. Omron and Allan Bradley are probably the two strongest proponents of Device Net. The Omron Device Net configuration software is far easier to use, and more powerful, than the Allen Bradley offering.