I am using a hht to program my slc 500. The comm & run light come on but my I/O lights don't. I set the hht to the right cards in the right slots. Im thinking I got fubar on these mods because the mods that were in there before were working when i first turned it on. The mods that are not working is an ib8 & ob8. does anybody know what could be wrong?
I/O mods not working
- Thread starter zorin87
- Start date
briancr
Member
fubar = f&^%$# up beyond all recognition, thats the only one i know 
rdrast
Lifetime Supporting Member
fubar is correct above.
hht is correct above.
mods = Modules.
ib8 = 1746-IB8 24VDC 8 channel digital input module.
ob8 = 1746-OB8 24VDC 8 channel digital output module.
------------------
Did you change any wiring? Sounds like you are missing a 24VDC supply. If I recall correctly, the LED's at least on the input modules should light up even if the SLC Processor is off, if they are connected properly to a power source.
hht is correct above.
mods = Modules.
ib8 = 1746-IB8 24VDC 8 channel digital input module.
ob8 = 1746-OB8 24VDC 8 channel digital output module.
------------------
Did you change any wiring? Sounds like you are missing a 24VDC supply. If I recall correctly, the LED's at least on the input modules should light up even if the SLC Processor is off, if they are connected properly to a power source.
No I have not wired anything to them yet,but the input and output lights should come on without any power supply,when I program them to all be on. Also another problem is when I put the program in run mode it goes automatically back to default mode.
rdrast
Lifetime Supporting Member
And how exactly is an input light supposed to come on with nothing connected to it?
Here are the wiring diagrams for the input and output modules. Start there.
Here are the wiring diagrams for the input and output modules. Start there.
rdrast
Lifetime Supporting Member
NC Statements make inputs come on? Okay... Whatever.
briancr
Member
wow, our first instalation without any wiring, just think how small we can make the control cabinet. just the plc and a power supply and everything just works magically
Also this is going to make a broken / shorted cable obsolete.
And just think, it will be half the cost to build a machine
Also this is going to make a broken / shorted cable obsolete.
And just think, it will be half the cost to build a machine
bernie_carlton
Lifetime Supporting Member + Moderator
zorin87:
In case you haven't detected it, your knowledge concerning the SLC500 system and especially how inputs function is limited.
1. Inputs are not used as the targets for OTE type instructions. If you did this it is probably why the program doesn't run.
2. The input lights will only turn on in response to the appropriate signals being applied at their terminals.
3. If you don't already have it download the 'Getting Started Guide' for the hand held terminal available here.
In case you haven't detected it, your knowledge concerning the SLC500 system and especially how inputs function is limited.
1. Inputs are not used as the targets for OTE type instructions. If you did this it is probably why the program doesn't run.
2. The input lights will only turn on in response to the appropriate signals being applied at their terminals.
3. If you don't already have it download the 'Getting Started Guide' for the hand held terminal available here.
The Plc Kid
Member
Lets get basic here. Inputs module lights will not come on unless voltage is applied but outputs will if forced or the logic is turning them on.
When you apply voltage to a input point you are in essence only turning on a light with that voltage. The input and output modules use opto-isolators which see this light and tell the plc that voltage is present on that input.
When the output turns it is sort of reverse in a sense. When the output turns on its led the phototransistor activates the output circuitry to close. the output closing circuitry varies depending on what kind of output module it is ac or dc out or relay.
When you apply voltage to a input point you are in essence only turning on a light with that voltage. The input and output modules use opto-isolators which see this light and tell the plc that voltage is present on that input.
When the output turns it is sort of reverse in a sense. When the output turns on its led the phototransistor activates the output circuitry to close. the output closing circuitry varies depending on what kind of output module it is ac or dc out or relay.
allscott
Member
- Join Date
- Jul 2004
- Posts
- 1,332
Wow, I hope your using the PLC to learn and aren't actually trying to control anything with it!
Similar Topics
Hi All,
When setting up a CP441-2 with 2 IF modules how do you go about addressing the second IF module does it just follow on from the...
I have a SLC 5/03 with a device net card installed. I have much more exp with DH and don't know if conducting a simple program mod uploaded could...
Basic question here from a newby. We have an SLC 5 series PLC which was connected to an old PC running NT and Paragon OIT software. The...
I feel like this is probably a very simple thing I am overlooking.
(Compact Logix Studio 5000)
This is my first time using the predefined...
I am creating a project with WinCC Unified v16 Upd6 (PC runtime) with an S7-1200. The communication is good between the PC and the PLC as I can...
