Minimal PLC
Minimal PLC
(OP)
I have an application where I would like to be able to monitor maybe 6 analog and 6 digital points. I'd like to be able to just buy a real small PLC in a box and then plugin to a laptop to view the point status, alarms, etc. I also need to be able to send the alarms to a remote building management system that talks Modbus. I'm looking for cheap and dirty because it's only temporary. Has anyone done anything like this?





RE: Minimal PLC
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If we learn from our mistakes I'm getting a great education!
RE: Minimal PLC
The DL series of PLC's are made by Koyo. Koyo has been making PLC's for a long time. They manufactured the original Series One PLC for GE. http
Automation Direct is typically a low cost source of automation suppliies.
RE: Minimal PLC
You might also consider the Eaton/C-H ELC line, which starts at $99 and has RS485 for Modbus. Programming software is free. The documentation and software are not even REMOTELY close to the quality of the Koyo (massive boo to Eaton!), but if you are willing to work at it you can figure it out. And the product does appear to reliably do what it claims.
I am using the Eaton PV28 "high performance" controller, because that base PLC will accept TWO moderately fast quadrature encoders with NO added hardware, for only $299. Try that with a Koyo and you will rapidly run through dollars.
RE: Minimal PLC
RE: Minimal PLC
I've used them several times with generally good results. The price is right. The manual is less than great.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Minimal PLC
For example, Teco SG2 ($80+) has only 200 lines or 99 function blocks of program memory vs. 4.5k memory in Eaton ELC-PB14 ($99). Granted, the SG2 does have a unit with 8 analog input for much less than the ELC... just depends on your needs!
I think it's cool that there are so many options in low level devices these days. There are a lot of solutions to your problems. Has anyone ever used the EZAutomation.net products I stumbled upon the other day? American made? What's that? ;)
RE: Minimal PLC
RE: Minimal PLC
And Yes TECO's manual is horrid but you can't beat the price.
Keith Cress
kcress - http://www.flaminsystems.com