Installation manual

Publication 1747-RM001G-EN-P - November 2008
G-26 Application Example Programs
When the SLC processor sets both DN and DA for a MSG instruction, the MSG sequence to an
Enhanced BAr Code Decoder is complete. In this case, the decoder has received the “Read”
command and has formulated a reply to this command. Therefore, unlatch B3/2 at this time to
be ready for the next “REad” request. In addition, when DN and DA are both set, this indicates
that the data received with the read reply (except “no-read” data) is valid and may be buffered
or used.
If an error occurs with the MSG instruction, the ER bit is set. If this occurs, the user can either
try to resend the same message again by unlatching EN, or at this point, could sound an alarm
or route the product down a rework loop or some other similar action. If the latter choice is
used, you must also unlatch B3/2 at this time to be ready for the next “Read” request.