Forgot How To Address 1791 Remote

I have a PLC-5 system with four racks already attached. My last rack is a remote that starts at 40/1 40/2 etc. I need to add 3 more 1791-oa16 remotes to the system. How will my addressing of these remotes need to be done. Will one be 50/1, 2, , 3,etc. then 51/1 etc? HELP thank you

Greetings EDWARDO,

I’m not sure that I understand exactly what your existing addressing is set ... the syntax for the addresses that you listed is “unorthodox” ... but here’s the best that I can do with the information that you’ve posted so far ...

the best way to get a handle on the addresses is to add them to this screen ... (either manually or by Auto-configure if you’re online) ...



notice that each remote chassis MUST begin with an even-numbered “Group” setting ... in other words, 0, 2, 4 and 6 are valid entries ... anything else won’t work (including some that you listed in your post) ... also, the smallest allowable chassis size is 1/4 rack (translation: 2 words of input table - and 2 words of output table) ... that means that even though each of the 1791 units that you mentioned has only 1 word (16 bits worth) of actual outputs, you still must allow for the other “wasted” words ...

to nail things down, if you use the settings that I’ve shown above, your new remote units will have the following bit addresses ...

first unit  = O:050/00 through O:050/17 

second unit = O:052/00 through O:052/17

third unit  = O:054/00 through O:054/17

if this doesn’t answer all of your questions, then it might be a good idea to post a screen shot of the Channel Properties window (as above) showing how your existing system is already set up ... we can go from there ...

hope this helps ...

Thank you

Ron

Sorry I may have not been very specific. Can I send you direct to your e-mail a copy of the program so that you can look at it .

Ron sorry to keep bothering you. I was wondering on the dip switch settings on these remotes. Since these are the only remotes other than a panel view in the system do I set them as Rack1, Rack2, rack3, according to the allen bradely spec sheet. I understand how to set it up in the plc now and shouldn't have to send you a copy of my print..Thank You

Greetings EDWARDO,

here’s my “best guess” on the DIP switch settings - based on what I think I understand about your system ...

-------------------------------

first unit = Rack 05, Group 0



SWITCH #2 - TOP

[0    ] 8  

[0    ] 7

[0    ] 6

[0 ?  ] 5  

[0 ?  ] 4

[0    ] 3

[     ] 2

[     ] 1



SWITCH #1 - BOTTOM

[0    ] 8

[0    ] 7

[0    ] 6

[    1] 5  

[0    ] 4

[    1] 3

[0    ] 2

[0    ] 1



-------------------------------

second unit = Rack 05, Group 2



SWITCH #2 - TOP

[0    ] 8 

[0    ] 7

[0    ] 6

[0 ?  ] 5

[0 ?  ] 4

[0    ] 3

[     ] 2

[     ] 1



SWITCH #1 - BOTTOM 

[0    ] 8

[0    ] 7

[0    ] 6

[    1] 5 

[0    ] 4

[    1] 3

[0    ] 2

[    1] 1



-------------------------------

third unit = Rack 05, Group 4



SWITCH #2 - TOP

[0    ] 8  

[0    ] 7

[    1] 6

[0 ?  ] 5  

[0 ?  ] 4  

[0    ] 3

[     ] 2

[     ] 1



SWITCH #1 - BOTTOM 

[0    ] 8

[0    ] 7

[0    ] 6

[    1] 5  

[0    ] 4

[    1] 3

[    1] 2

[0    ] 1



-------------------------------

pay very careful attention to the DIPs that have question marks ... these are pretty specific to your own system and might have SAFETY implications ... I’ve set them the way that “most” systems are set - but that could be totally wrong for your application ...

on each SWITCH #2, DIPs 1 and 2 have been left blank - these control your communication baud rate ... since you didn’t post the screen shot, I have no way of knowing what baud rate your existing system is using ... you’ll have to research this and pick the settings that will match your existing baud rate ...

most of the information that you’ll need can be found in this manual ... pages 4-2 and 4-3 are a good place to start ...

and VERY important! ... after you change any of the DIP switch settings, always turn the power to the unit off and then back on ... the settings are only “registered” when the unit first powers up ...

as I said earlier, these are just “guesses” based on what I think I know about your system ... hope this helps ...