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Choice between Opto-22 and ControlLogix 2

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teststandcharlie

Industrial
May 31, 2005
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Hi,

I am specifying controls for a system that will have approximately 150 I/O, thirty or so analogue inputs. I will be communicating to PID controlers and high limits using Modbus/RTU. For several reasons I'd like to distribute the I/O using Ethernet and use two processors, as well. Part of the I/O will be in a room that is usually 100F ambient. I plan to use at least one touch screen HMI. I am looking closely at the Opto-22 SNAP, using ioControl software, or Rockwell Automation Contro/Compact Logix. Any thoughts or experience?

Karl

Karl Wm. Klein
Karl Klein Design
 
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I like the AB hardware, simply because it has higher density I/O modules than the Opto-22.

xnuke
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Thanks xnuke, I have kong used AB hardware and agree regards the I/O density. I go back to PLC2 with AB, but have only experience with the Opto-22 I/O modules. I am hoping someone out there has some experience with Opto in terms of reliability.

Karl Wm. Klein
Karl Klein Design
 
I use the opto-22 SNAP I/O over an Ethernet connection which is driven by a DOS target, using a 16-bit operating system. Been working trouble free so far.

The only problem I encountered was my own failure to carefully read the manual. I did not take into account that the SNAP "Brain" reads and transmits in reverse byte order from the Intel based PC-104 card I am using (Big Endian vs. Little Endian byte order). Once I solved the byte reversal my program interfaced just fine to the unit via the Ethernet using a TCP/IP stack. (Note that the unit actually accepts the commands in IEEE-1394 format).

Overall I can recommend the unit, and give high marks to their tech support crew.
 
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