Friday, March 1, 2024

Puzzles in Symphony Plus

To mark my return to blogging about DBDOC and INFI 90, I pose some puzzles.

FC 116 - Jump/Master Control Relay

I have always been curious about this function code. It is able to "jump" over block processing and

  1. and leave the skipped blocks unchanged S3= 0
  2. or zero the skipped non-forced rung blocks that are jumped S3= 1
We have data from 600 active and prospective DBDOC builds over the years. Fewer than 5% of these INFI 90 had this function block. Furthermore, many that had it at some time in the past no longer use it.

The block appears to still be supported in SPlus Engineering.

Can anybody add insight to the current thinking about FC 116?

UCB and SPO/PGP Graphics

Once upon a time, SPO SPlus Operations graphics were PGP and used files with extensions .UCBG, .UCBV and so on. This continued into SPO, where the WORK folders used them.

It is obvious that the UCB initials meant something. Can anybody indicate what those letters stood for?

Chaining of FC 126 RDEMUX Blocks

We find numerous FC 126 blocks that have the value of S3 "Block address of next block in link list" incorrect. Here is an example:




Is this an issue? Is it not an issue because the chained RDEMUX block is not used? Are there ramifications that are not apparent from the documentation?

In DBDOC builds, the error codes [316] through [319] and [325] are have the attributes that they report things that violate the rules, but we do not know if they actually cause a problem other than not actually working. If the result is not used, who cares? 

What I could check had the badly linked blocks unused generally. The puzzle is if this ever is worth reporting.