Swift Futura riser failure

We are having a challenge on a Job. They are 4 lifts at the building with two risers. We lost communication on riser #1,so only riser #2 is working i.e. the side with lifts 3 & 4. In other words when passengers press the hall buttons on any floor, only on riser #2 side does the button light up. This problem started from nowhere only yesterday. At the moment only two lifts are working, these being lifts 3&4. Lift 1 is under repair awaiting a rope change but is in running condition. Lift 2 is completely out of order and is due for replacement. The building has 17 landings so HPU remote stations are addressed from 1 to 17, the bottom landing has address 1 and the top has address 17.The other riser is addressed from address 25 to 41, the bottom landing has address 25 and the top landing 41.The riser which has addresses 25 to 41 is the one not communicating. We checked our supply line which is VH+ and VHC and our 24v dc is there. We checked our data communication which is HCRT+ and HCRT_ for continuity and its ok on all 4 lifts and shaft. We also checked our CTG cables across all 4lifts including the ones which are currently off since they are all in the group. We then went on and exchanged HPUs from riser #1 to the other and the fault from riser#1 transferred to the other riser #2. We then checked the software side where we checked SCA function which shows floors which are blocked but it was ok. It therefore means that something or a parameter has disabled all the HPUs on riser#1. so I need help on how can I make riser #1 communicate again.

Please assist by pointing us to the possible parameters needing to be checked. So far we have done comparisons between the parameters on the two risers and have not found anything different between them. We are however certain that we are missing something

Who is Master and Slave in that setup?

Excel,

If you’ve swapped all hall p.b. Boards, and your trouble followed the swap, I would suspect it’s a hoist way board issue.
*Do the power LED light up on the hall station HPU’s for riser #1?
*Does your push button configuration use that HPU Termination Board at the bottom of the riser? If so, I might suspect that board as it’s common to all HPU’s on that riser.
If the hall station addresses match the CEC print, you’re good there.

Please feel free to contact Issa Lwaysi from Miltronics Inc. @ (917) - 417 - 7389. We provide FREE Tech support for all CEC swift 5000, Futura, & Merida related equipment. 24/7 SUPPORT