1A2 Multiline Phone Control Board - Rotary/Interlink/Pic, REV-G

[Update 06/27/19] Received the REV-G boards from the printer a week ago, and soldered two up to test the synchronized interlink feature:

Component side

Solder side


History of Board Revisions

1A2 KSU - Revision G

Closeup of REV-G board with a matte black solder mask

Eight 1A2 phones Interlinked with two REV-G KSU boards for a total of 5 active lines (4 CO and 1 Intercom)
with two PowerDSINE Ring Generators.

What's new in this revision is when boards are interlinked, the lamp flashing for all lines is synchronized. This was not true with the REV-F and REV-F1 boards, where the flashing rate for ringing and hold for lines 1+2 could drift out of sync with the flashing rate for lines 3+4, since the cpus managing the two sets of lines weren't synchronized. A single wiring change was added in Rev-G to synchronize flashing along with a small software modification.

Otherwise, this revision offers the same features as Revision F and F1: 2 lines / 4 Extensions with intercom on Line 5, expandable to 4 lines / 8 extensions if two boards are interlinked with a ribbon cable. Both DTMF and Rotary dialing are supported for buzzing extensions via the intercom line. And all the standard 1A2 features for lamp flashing, hold, call transfer, CPC, and programmable multiline ringing.

When combining two boards to provide a total of 4 CO lines and 8 extensions, extensions can be uniquely dialed on the intercom line via Touch-Tone or Rotary. This page shows how to interlink two boards.



Board Layout And Schematics