CDM1550 and HT1250 Emergency Question

[jghqaltga5926]

Hello Everyone!

Alright, so my department was fortunate enough to be donated several CDM1550LS and HT1250LS radios. I know these are older, but due to funding and size of the department this is perfect! I'm new to the CPS programming, but I've had luck through the internet with answering most of my questions. I know these are old radios, but they're new to us and what we could afford.

A problem that I'm facing is the emergency button on the HTs. My goal is to have the emergency button be pressed and the CDM decode it and show radio XYZ is in alarm. I somewhat have what I'm looking for, but believe I'm missing a key part as well. Basically right now on CDM I have scan list of normal com channel (CH1) and a secondary on emergency channel (CH2) . Emergency channel is strictly "listening" for emergency button activation. I have CH2 set to priority 1 scan.

HTs go into emergency mode fine and the CDM picks it up fine, but my problem arises if there's other traffic on CH1 while emergency is pushed. If CH1 is active the scan doesn't seem to pick up CH2 until CH1 traffic has stopped. I have played with the impolite and polite tries, but what I don't like about this is that the entire time the HT is trying, if the PTT button is pressed the tries stop. Also, if the tries stop but CH2 on CDM never got scanned the emergency could go missed.

My question is, is there some programming that needs to be done on either the CDM or HT that confirms the CDM received and decoded the alarm so the HT does not need to continue with the polite and impolite trying? Currently the HT will go through all it's tries regardless if there's traffic on the CDM and even after the CDM displays and alerts of an emergency on it's screen.

A second question I have is with the HT during an emergency. Is there a setting or something that lets the HT user know they activated the alert besides the initial little "beep" and screen showing. My only though is in a low light/loud environment will the user know if the emergency button was activated easily?

 

[K2NEC]

Sounds like you have the right idea with priority scan you just don't have it set up properly. Ensure that both Ch1 and Ch2 are set up in the same scan list and the scan list has Ch2 as priority channel #1. When you open up the scan list it should say "Priority 1 (First Scan List Member)" So make sure this is checked and the first member in your scan list is Channel 2.

As for the beep there is nothing else you can do. TRBO radios have sort of a "search tone" that is very loud and distinct but I have not seen this on Waris radios.

 

[jghqaltga5926]

Thanks for the reply. The scan issue may not be as big as I believe, but it'll take some more checking tomorrow. I do have it set where CH2 is priority, and thought I tried it where CH1 had traffic. I may be mistaken, but I thought if CH1 had traffic, and the button was pressed, the CDM didn't see it if CH1 had traffic longer than the tires.

With that, is the CDM supposed to send a signal or code to the HT acknowledging the emergency signal so the HT can stop with the impolite and polite tries?

 

[Floridarailfanning]

With that, is the CDM supposed to send a signal or code to the HT acknowledging the emergency signal so the HT can stop with the impolite and polite tries?

I believe there should be a setting in CPS that allows you to configure the radios to acknowledge the emergency activation, but by default, the receiving radios won't do this. Typically a base station or the dispatcher's radio will be used for this. On the Mototrbo radios, there is a field called "Emergency Alarm Ack" and this same option should exist on the older radios.

 

[jghqaltga5926]

Just want to clarify that the receiving radio (which I'm wanting to acknowledge the alarm initiated by the HT) is the CDM. I believe I have previously had the ACK Alarm checked but can't confirm. Would this need to be done on the mobile or the HT or both? Currently the HT does not have it checked and the CDM has the emergency (under signal config) is disabled. The CDM still decodes emergency traffic, this just means the mobile can't go into emergency mode which is fine.

 

[Floridarailfanning]

The alarm ack should only need to be used on one of the CDM's to acknowledge the HT's alarm activation, while all of the other of the radios can be configured to decode emergency alarms. This helps prevent over-the-air collisions between multiple radios which all attempt to acknowledge the alarm activation simultaneously.

 

[jghqaltga5926]

Is there another place that the CDM must have alarm ack checked. The only please I’ve found it is in signal config under the emergency tab. It was my understanding that this tab was for the radio in question ability to broadcast an emergency alert. On the CDM I have emergency disabled because it does not need to send an emergency alert only decode and acknowledge it.

 

[N1GTL]

MDC emergency channels should have one radio for ack and NOT be scanning. The first part of the MDC emergency can get cut off and it will not work. ONE CDM1550 with ONE CHANNEL that the emergency reverts to. Any other set up you're risking it not working.

 

[jghqaltga5926]

So to confirm. You're saying one CDM should be dedicated to only being on the emergency channel? This would require two CDMs per apparatus. I thought if you set the emergency as priority 1 in the scan (white the HT has X# of retires), the CDM will scan the priority channel (emergency) at a preset amount of time.

This is/was my understanding:
If CH2 is priority and the radio is scanning between CH1 and CH2, while traffic is on CH1 the radio is still looking for a carrier on CH2. If a carrier is heard on CH2 (priority) it will revert to that channel. If the HT has a few retries it (CDM) may miss the first try but the second one shouldn't have a problem correct?

When an HT activated the emergency button, what exactly is happening? Does the CDM have to transmit (actually transmits) a code of acknowledgement back to the HT? If so how/where in the programming can I confirm that the CDM "knows" it needs to send an acknowledgment and where in the programming does the HT know to look for said acknowledgment. Lastly, once the HT receives the acknowledgment, does it stop the tries or continue with the present number of impolite and polite tries?

Thanks again for all your continued help. This is the only issue I haven't been able to figure out with these radios.

 

[K2NEC]

No, only 1 CDM needs to acknowledge the emergency. This means that the radio will transmit back a packet of data saying that the emergency was received. The apparatus can have normal CDM's (just one) that will display that an emergency was received but they won't be sending that acknowledge packet to the emergency radio.

When your HT1250 activates mandown it sends an MDC1200 packet saying that the radio is in distress. Any CDM and other HT1250 can be programmed to display that radio 1234 is in emergency. When the CDM you are looking for to reply does so it will send out another MDC1200 packet to the emergency radio over the air pretty much saying "I receive your emergency" and it stops the HT1250 from transmitting any more emergency packets. The CDM that are in the fleet do not need to ack the HT1250 and should not ack the HT1250 for reasons stated above.

 

[N1GTL]

EXACTLY what K2NEC said. ONE radio needs to ACK the emergency so it does not go into polite and impolite retries. That does not not mean other radios cannot display it but only ONE radio should ACK!

 

[jghqaltga5926]

Thank you for that explanation and both of your responses. That makes a lot of sense and helps with the concerns for multiple radios.

In the programming of the CDM was exactly do I need to ensure is correct in order for that CDM to send the acknowledgement. Is this is in the signaling-signaling confirmation, in the MDC system programming, or in MDC message?

Thanks in advance for all your help!

 

[K2NEC]

In Signaling>MDC System the "Emergency Decode" needs to be checked

If you go to Signaling>Signaling Config and Emergency tab is where your HT1250's should be programmed. That's how the encode for emergency is setup.

I think I am missing one more thing. Anyone want to tag in here and help me out?

 

[jghqaltga5926]

Is the first part in the CDM or the HT. I have the Ht portion correctly programmed already, but thanks for the confirmation.

Currently the CDM decodes the emergency, but doesn’t appear to send an acknowledgement as the HT continues with it’s all it’s impolite and polite tries.

 

[K2NEC]

Huh. What is the model number of the CDM?

 

[Floridarailfanning]

If I recall correctly not all of the CDM's support some or all of the MDC/emergency features on conventional personalities. I had a 1550LS+ a few years back the actually only allowed MDC on LTR trunked personalities.

 

[jghqaltga5926]

It’s a 1550LS+. As mentioned above it can, and does, decode the emergency activation by the HT. It just doesn’t seem to sent an acknowledgment packet.

What are the settings needed on the CDM I order for it to send the acgknowlddment packet.

 

[Floridarailfanning]

It’s a 1550LS+.

I believe K2NEC was referring to the long model number. The radio I previously had which did not support MDC in conventional mode was an M25KKF9DP5AN.

What are the settings needed on the CDM I order for it to send the acgknowlddment packet.

As I alluded to above, I don't know exactly where in CPS the checkbox for the Ack is, I just know there should be an option to enable or disable it somewhere. Sorry for not directly answering the question. . . It's been quite a while since I've dealt with the Pro/Warris radios and MDC Emergency settings.

 

[jghqaltga5926]

I gotcha. I’ll have to get the complete model number tonight.

I agree, there is something that should be checked or selected, but it’s where to do it that’s the difficult part. It’s somethkng simple, just can’t figure it out.

 

[K2NEC]

I believe K2NEC was referring to the long model number. The radio I previously had which did not support MDC in conventional mode was an M25KKF9DP5AN.

As I alluded to above, I don't know exactly where in CPS the checkbox for the Ack is, I just know there should be an option to enable or disable it somewhere. Sorry for not directly answering the question. . . It's been quite a while since I've dealt with the Pro/Warris radios and MDC Emergency settings.

Yea exactly. The older versions of the LS+ only had 18 channels and didn't support MDC signalling. Not saying that is the problem but it's possible. Also, I checked the software up and down and I can't seem to find that check box. I checked in the personality and in the MDC system but came up with nothing. TRBO radios make it so much easier lol.