DL260 IBOX 700 series for comm's

[8bits]

The instruction manual indicates the status bits (error) can not be used elsewhere in the program.
I did use an error bit to enable a comm error LED on one of the output bits (Y0). I had the error bit latch another bit for error indication. On a another rung, I tried to use the falling edge to clear the latched error condition.
Any suggestions on how to latch a comm error (using DirectNet) and then resetting when the comm error clears?

[Greg]

If the manual says "the status bits (error) can not be used elsewhere in the program", I think what it means is simply that you shouldn't duplicate their usage. But you can certainly use them to trigger other things like you have stated.

The Success and Error bits are immediately cleared (reset to zero; RST Success, RST Error) as soon as the IBox is executed. A typical latch with reset is like this:

   C0       C1                                   C2
--] [--+--]/[-------------------------( )--
   C2   |
--] [--+

C0 might be the IBox's Error bit. C1 is the reset and is normally OFF. So when C0 comes ON, C2 comes ON and latches around C0, so that even if C0 goes back OFF, C2 still shows that an error occurred. Then you would set C1 to ON to clear the latch. Of course, there are many other ways to do this... for example, the following would do the same thing:

   C0                                                C2
--] [---------------------------------(SET)--
   C1                                                C2
--] [---------------------------------(RST)--

Is this what you are asking?

[8bits]

 :)Thanks Greg. That is what I thought I was doing. I latched the error bit and had that turn on an output - that worked fine. The method of test/verification was to simply disconnect the data cable. However, I did not seem to be able to clear the latch when ever the the cable was reconnected. I will go back and enter in the sample rung examples and see what happens. Does it matter that I am using IBOX701 (RX) for multiple data?
Example: I am reading the slave TA0, a VMemory location that is incremented and also the VX0 slave input memory. The reads all come through with no problems. I am wondering if having multiple error bits due to the multiple IBOX instructions might have any bearing on this?

Another , but different subject: The manual indicates that the DL260 serial port#2 can only use the raw ASCII as either in or out but not both. I don't understand why that would be the case as when using DirectNet , both TXD and RXD or used? I am interested in incorporating an external micro based serial I/O to communicate with the PLC using only ASCII in/out.
Thanks


EDIT:: After doing a little more trial coding, I think the bottom line I am unable to use, as in you example above, the actual error bit (C0 example) except to latch it. It seems that I cannot use the bit to check for
-|/|- .
In other words, you can not use the error bit to clear a latched error bit using the scheme mentioned in your post.
Thanks

 Update: Well. I wasn't using the 'success' bits to clear the latch, that worked fine.