Batboard

Did a search on this one, but nothing...

We recently upgraded a conventional system from a SpectraTac comparator with MTR receivers (and a couple AstroTac receivers) to an ATAC3000 comparator with all AstroTac receivers and Quantars for main/alternate transmitters. All connections to the comparator are v.24 hybrid over microwave (Mot PTP system with RAD MUX's for audio and RAD SPS3 and FPS8 for the v.24 connections). The Gold Elite is controlling the repeater with regular TRC commands to the DIU.

For some reason, as soon as we connected the new comparator and DIU, the MDC system was rendered useless. No ID's are showing up on the resource, but they were before the changeover. The MDC packet is passed by the DIU; you can hear the subscriber's post-ID at the console. I also verified that Inbound PTTID is included in the dispatch capabilies for that resource. There were no changes to any hardware in the CEB.

I can't think of anything that would be screwing with the MDC except the DIU, but I cant find any settings that seem off.

Any suggestions?

Where is the audio output from the DIU being connected to at the console? Gold Elite still needs its MDC modems and associated cards to get the ID's from the DIU unless ACIM's have been installed, but I don't believe that will give you MDC ID's, just ASTRO ID's.

You need those MDC modems back in the console and the audio routed to them to get your analog MDC ID's back.

Sorry, forgot to mention that...

DIU connects 2W to the P2 punchblock. The BIM hasn't changed from its original configuration which includes an aux card and a StatAlert modem. Originally with the Spectratac, MDC worked great. Now we have nothing.

Obviously, the audio was tuned on the BIM, but no other configuration changes.

Is there an ACIM integrated into the system at all? It's possible that when the system configuration changed, the resource that the DIU is connected to (BIM) no longer has an MDC modem associated with it, hence the reason you aren't getting decoded ID's.

Check your CDM configuration on the Centracom server or supervisor console and see what gives.

Nothing changed with the configuration of the resource in teh CDM. It's still set up as a signalling T2R2 resource with stat alert as the signalling type.

Does it matter whether the console connection to the DIU is 2 or 4-wire? Right now it is 2 wire, but it was 4-wire before when the BIM was connected to the SpectraTac.

IMBEJames wrote:Does it matter whether the console connection to the DIU is 2 or 4-wire? Right now it is 2 wire, but it was 4-wire before when the BIM was connected to the SpectraTac.

It very well could. As a test, you could temporarily jumper the 2 wire and 4 wire lines. Just for a moment and see if it decodes.

Rewired the console connection for 4-wire and reprogrammed the DIU for 4-wire today. Everything works fine now. Thanks everyone...

You definitely want a 4-wire configuration for any sort of public safety application in my opinion. It gives you the ability to continue to receive while transmitting, so if a unit interrupts dispatch, you can hear the unit while the console is in TX.

This is of course provided you are using a duplex system, not simplex base stations.