PLC5/20

[william 0]

One of the analog channel of the module is faulty as such I have to relocate the input to another spare channel which is avialable in this case. The plc is an alan bradley plc cpu type plc5/20 the analog is mounted on the slot9. I could not figure out which N file for the new channel to use. The current n file is N10:18. In the program it use BTR & BTW.I have attached a picture file of the rung. How do I know which N file to use for the new channel.I would appreciate if any expert out there could help.

[chelton 66]

What is writing to N10:18 , the BTR and BTW in the attaced image is using N23:** . Do you know the module part number?

[Ken Roach 194]

The BTW size of 37 Words and BTR size of 20 Words is typical of the 1771-IFE Series C module, which is a very common Analog Input module for the PLC-5 controller. I see from the screenshot that both the BTR and BTW are Enabled at the same time... this suggests also that there is a programming error, because for a 1771-IFE the BTW (configuration) should only be written once to configure the module. Are you planning to move this analog input channel from one module to another, or from one channel to another channel on the same module ? The 1771-IFE module is configured using jumpers that are accessible from the side of the module, to set up each channel as Differential or Single-Ended, and to set them for Voltage or Current input. It is very important that you configure the new channel the same as the old one when you move this input signal ! The Installation Instructions for the 1771-IFE describe the wiring arm connections and the jumper settings: http://samplecode.rockwellautomation.com/idc/groups/literature/documents/in/1771-in045_-en-p.pdf As mentioned previously, your screenshot also does not match the address you stated for the analog input point, so you need to do some additional research about which module you are working with. Post more information about the PLC-5 chassis size and what kind of modules are installed. What kind of signal (voltage or current loop) is being used on the affected analog channel ? How have you verified the presence of a valid input signal ? Edited 12 Aug 2011 by Ken Roach

[Mickey 71]

And it would be much easier for someone to help if you post your whole program, the .RSP file.

[BobLfoot 301]

William - Please take the following as friendly advice. You can improve the ScreenSHots you are posting with the following suggestions: IN WINDOWS - Basic Screen Captures: 1. With what you want showing on the screen press the PrintScreen Key. 2. Next open the program paint and from the pulldown menu execute the command EDIT - PASTE. 3. You will now ahve your screenshot in a paint file. 4. Next do a File - SaveAs and select type jpg or jpeg. DO NOT USE Bitmap or BMP the files will be huge potentially. IN WINDOWS - More Advanced Stuff 1. Look for freeware programs like TechSmiths SnagIt for example In LINUX 1. Most modern Linux Distros have a built in ScreenShot Utility. Use this.

[Mike Lamond 1]

Bob, For screen captures, I prefer to use png (Portable Network Graphic), which is a lossless compression format, instead of jpeg, which loses some information. For programming screen shots, with large areas of solid color background, the file size difference isn't that much and still far smaller than bmp files. I've seen some jpg images where small characters were blurred just enough to be ambivalent. With png files, the image will always reproduce the original sharpness.

[BobLfoot 301]

Bob, For screen captures, I prefer to use png (Portable Network Graphic), which is a lossless compression format, instead of jpeg, which loses some information. For programming screen shots, with large areas of solid color background, the file size difference isn't that much and still far smaller than bmp files. I've seen some jpg images where small characters were blurred just enough to be ambivalent. With png files, the image will always reproduce the original sharpness. Mike points out another good choice png also works well.