Verifying a program and going online with rslogix 500

[Stuartjl 0]

Hi, i need to modify a program in rslogix 500. I'm use to using mitsubishi's gx developer, so i base my experience on veryifying, going online and downloading from this. So first of all, i want to verify this existing program is the correct before i do any modifications, then do a download. The PLC'S that are used are SLC500's one with serial and one with ethernet. The mod i will be doing on one PLC is replacing an existing analog input card with a digital input card. The other PLC i will be modifying will have code added, so i can read an analog input then output this value to SCADA. Can one give any advice on the steps to do this? Ive had a look at a few youtube videos but just need a little more expert advice. Thanks Stu

[daba 4]

The changes you have to do to the first PLC will have to be done offline, then downloaded, as it involves modification of the I/O.. This will have to be carefully coordinated if the PLC contains any useable production data that you need to preserve through the changes. Making changes offline requires that you have an up-to-date online "image" of the code. Data-table values that change after you have been online and "saved" will be overwritten by the subsequent download. The second SLC can have the code added while online, so no downtime is needed, and no data will be lost. It may be that your SCADA can simply read the existing analog input from the input image, and apply any scaling needed. As is always the case, more info is needed what you want to do. Edited 6 Jun 2014 by daba

[panic mode 246]

1. if possible get another plc/system just to practice / gain experience. 2. figure out how to go online with each plc. 3. backup each of them (always make a copy) 4. study programs to understand how they work. 5. since you are not familiar, plan for (sufficient) downtime. one of system with hardware change must be restarted, so at least some downtime is required. other potentially could be done without stopping plc at all.

[Stuartjl 0]

[Stuartjl 0]

Thanks for that :) i think i'll tackle the online mods first as they seem to be easier than going straight to installing a new card on a remote io scanner.