adccommunitymod (AutomationDirect) asked a question.
DL05 - Detection of modules
Created Date: July 18,2008
Created By: jondecker76
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Is there a way to detect the presence of addon modules? I would like to detected whether a 4ch analog in or a 8ch analog in is present. Any ideas? Thanks Jon
Created Date: July 18,2008
Created by: KPrice
jondecker76, In DirectSOFT, while connected to the PLC, at menu bar, click PLC> Configure I/O...
This should show your I/O configuration.
You can also ask the PLC to check the I/O configuration at power up: at menu bar, click PLC> Setup> I/O Config Check...
This works for our DL205s. We do not have a DL05 to test right now. Hope this helps.
Created Date: July 18,2008
Created by: franji1
If you mean programatically in the PLC, the answer is NO.
However, somebody on this forum came up with a cool way to figure out if discrete input module existed by looking at the values. I don't know if that can be applied to analog input since the number of channels must be configured.
If you have an analog input module, if somebody can remember the link to that discussion (the SEARCH doesn't work very well on this forum), please post it.
At power up, the guy used stages to clear some X memory, waited to see if any turned on, cleared it again, and then waited again to see if any changed, then set a flag (I think that was what he did).
Created Date: July 18,2008
Created by: allukes
The method is based on the fact that an IO input module will always update the PLC's memory on every scan if the module is present. So if you write to that data area and it changes then you can assume that the module is installed. If it's not there then the data will stay the same when you write to it. I think you could use the same technique with the analog modules. If the module is setup correctly then it should overwrite any data in its input registers written by the PLC program.
Created Date: July 18,2008
Created by: franji1
There's a big caveat. You have to "configure " analog modules before you can read any data, and part of that is knowing the number of channels. But he wants to determine the number of channels based of the data. But you need to know the number of channels to set up the data. But to set up the data, you need the number of channels...
OR, I bet you could use the good ol ' MULTIPLEX mechanism from the good ol ' days, and possibly THAT would work???
I found the topic - it's on the Host Engineering forum (doh!) http://forum.hosteng.com/index.php/topic,190.0.html
Created Date: July 19,2008
Created by: allukes
You would not be able to use an IBOX instruction but what if you manually set up the control registers? What happens if you configure for the 8pt and you have only a 4 pt module present? Does it attempt to write something for the last 4 channels or does it abort because the hardware is not present?
Created Date: July 18,2008
Created by: jondecker76
Is there a way to detect the presence of addon modules? I would like to detected whether a 4ch analog in or a 8ch analog in is present.
Any ideas?
Thanks
Jon