Win500 not accepting P25 tables

[DaveNF2G]

Win500 is not accepting the offset and step values that I am receiving from local VHF P25 sites. It resets them to zero when I move to the next field in the Trunking Tables window.

One example:

-Tables
#Format: Table ID,Base Freq,Spacing,Input Offset,Assumed/Confirmed,BandWidth
00,851.00625,0.00625,-45.00000,"Confirmed",0.00625
01,762.00625,0.00625,30.00000,"Confirmed",0.00625
02,136.00000,0.01000,5.97500,"Confirmed",0.01250
03,142.42250,0.00500,13.15000,"Confirmed",0.01250
04,143.43000,0.00500,15.66250,"Confirmed",0.01250
05,147.01250,0.00250,32.30000,"Confirmed",0.01250
06,136.00000,0.01000,8.18750,"Confirmed",0.01250
07,136.00000,0.01250,6.00000,"Confirmed",0.01250


I am entering the tables on the same numbered lines as are indicated in the above list (Table ID). Win500 will accept the base frequencies, too. But when I enter the Step (Spacing or BandWidth - not sure which one it's supposed to be as PRO96COM doesn't use same terminology:roll: ) or Offset, Win500 defaults them back to zero before saving.

This happens whether I use P25 AUTO or P25 MANUAL as the TSYS mode.

 

[DonS]

For its "Step" column, Win500 wants the "Spacing" field from your list above, and it wants the value in kHz (e.g. 6.250).

 

[DaveNF2G]

Ah-hah! OK, I'll try that. Thanks.

 

[DaveNF2G]

OK, PRO96COM's "spacing" adjusted into whole kHz went into the Win500 "step" column without a problem.

I still can't find a value that works in Win500's "offset" column. It occurs to me that this might need to be a hex value. But which decimal value from PRO96COM do I need to convert?

Also, Win500 has additional columns - Lo Chan and High Chan. If I need to fill those in, then where does that info come from? I can't really put in system information that hasn't been broadcast yet or values for channels that have not been announced.

 

[DonS]

Your P25 info in the original post is based on the "IDEN_UP" message from the CC. The "Table ID" (first field in each row) represents a range of channels. Each entry is 4096 channels, and there are 16 possible entries. ID 00 is channels 0-4095, ID 01 is channels 4096-8191, etc.

The scanner wants each entry to represent a range of channels, and doesn't use the "Table ID" values explicitly. For "Table ID 00", you'd set CH Lo = 0 and CH Hi = 4095. "Offset" is equal to CH Lo.

Your entries, based on the data in the original post, would be:

Lo Chan   Hi Chan   Offset   Base Freq    Step
0         4095      0        851.006250    6.250
4096      8191      4096     762.006250    6.250
8192      12287     8192     136.000000   10.000
12288     16383     12288    142.422500    5.000
16384     20479     16384    143.430000    5.000
20480     24575     20480    147.012500    2.500
24576     28671     24576    136.000000   10.000
28672     32767     28672    136.000000   12.500

Just out of curiosity... if the CC is sending this data, and if it's presumed correct, why enter it at all? Why not just set the TSYS to "P25 Auto" and let the radio figure it out? The radio will populate the table on-the-fly as IDEN_UP messages are received.

 

[DaveNF2G]

I thought P25 AUTO would only work on 800 MHz systems, similar to Motorola Type II, which has to be programmed with tables on every band except 800.

It might still be necessary on the older GRE models (PRO-96/2096), which appear to treat "P25" trunking as another flavor of Motorola - it's not a separate trunking type.

 

[DonS]

I thought P25 AUTO would only work on 800 MHz systems, similar to Motorola Type II, which has to be programmed with tables on every band except 800.

On the PSR-500/600, "P25 Auto" works on any P25 system that uses the IDEN_UP message to broadcast the table info. If you can get the data via PRO96COM, the radio can get it internally. (Presuming the data isn't contained in "multi-packets", that is).

In fact, if you leave all of the radio's table entries cleared out, set the TSYS to P25 Auto, then scan for a while, you'll see the entries populated in the TSYS.

EDIT: here's how the P25 TSYS/Table settings are used:
P25 Manual, T Tables=Default: use band-specific (700/800/900) internal table based on current CC frequency
P25 Manual, T Tables=Custom: use user-entered table
P25 Auto: use user-entered table, which is populated/updated from IDEN_UP messages

 

[DaveNF2G]

Thanks. Those details are helpful to know.

There is a possibility of multi-packet on one site that I can hear. The alternative is that new P25 sites do not transmit all of the necessary information to allow decoding of the datastream until they are ready to go into service. In any case, I hear what registers as a P25 control stream with a NAC, but PRO96COM doesn't decode it and the PSR-500 cannot decipher the SID.