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iTX fires a GPI on Vnode 401 via the GPI service on fwk 3B
The GPI in turn drives a Relay mounted above the VNode in the back of T17 – RL1 = GPI1 on TX412 // RL3 = GPI1 on TX414
The Relays are DPDT so 1 half drives the A U4000 & the other the B U4000 – An LED on the rear panel is lit
The U4000 senses the Relays via the COM Port – 2 Contacts are used the 2nd is set up to Transfer Softel Opt Relay 1 the other is Permanently jumpered to Transfer Softel Opt Relay 4
The Opt Module in the U4000 feeds into Line 16 (or 18) on the T3000 module – I’ve always only sent these out on Field 1 BUT if issues continue you could add in Field 2 (NB I don’t do this because I’ve seen this cause decoder switch bounce but that does depend on the decoder)
This can be seen as a standard but static TTXT Waveform on the WFM and you can see the Waveform move when the relay state is changed – It will also trigger the Test decoder rig in the rack next to the WFM. The spare output of the XVP can be easily patched to the Monitoring tielines so both the live & off-line XVP feeds can be tested
There is a new release of MSX due out that allows us to decode the opt pulses from the two U4000’s so we can see if both are operational until then the offline U4000 can be monitored via the “Subs DA” spare output or via the Matrix (Again monitoring the “Subs A or Subs B” input.)
We then monitor the GPIs on a Softel VFlex in U19 – Upper unit 172.16.217.147 is for TX412 and is currently driven from the TX DA – Lower unit is TX414 and I think is driven from the Erricson IRD which in turn is fed from the MCR Mux output
Relay detection triggers a Relay in the VFlex which in turn triggers a GPI on the Kaleido which is used to create the Tally for Ops
NB This is different to the CN France GPI which uses a Softel box in U17 that inserts the triggers downstream of the TX DA.