Yesterday afternoon a severe thunderstorm passed through Lapeer County and early on a bolt of lightning is believed to have struck the tower behind the 9-1-1 Center in Lapeer. A dispatcher witnessed an arch of electricity move from one of the stand-off antennas to a leg of the tower structure. The dispatcher also saw the tower glowing briefly. Subsequently, this lightning strike temporarily knocked out all communications in the center including sending the voice radio system into failsoft.
What is failsoft?
If the trunking system loses its control channel or has certain other failures, it is no longer able to operate in the trunking mode. So instead of going into a condition that stops all communication, the system enters Failsoft. In this state all transmitters (channels) turn on and operate in a ‘conventional’ repeater mode. The subscriber radios are able to recognize this state and switch to a predetermined frequency (one of the trunk system frequencies, but not the control channel frequency) depending on their selected talkgroup. In most systems several talkgroups will share a frequency. Some talkgroups may not be assigned a failsoft frequency and these talkgroups will cease to operate during the failsoft period. If a particular failsoft frequency has also failed, the talkgroups assigned to that frequency will also be off the air during failsoft.
The system quickly recovered and went back into normal operation. However, one system was unable to recover and that is the part of the paging system which dispatch’s EMS crews for Lapeer County EMS.
The old Zetron unit which runs the alpha-numeric pagers for Lapeer County EMS is no longer communicating with the paging servers. Several attempts to reset the unit and even change paging servers were unsuccessful. Another problem is that this unit has gone off of the Motorola maintenance contract several years ago. We do have replacement parts on hand for this unit, but working on it will cost the center time and labor. We will be contacting Zetron this morning to seek their assistance in diagnosing the problem and programming spare boards to be put into service.
As of yesterday, all bases of Lapeer County EMS (Imlay City, North Branch and two in Lapeer City) are operating on radio and telephone standby until further notice. It is not known when or even if this system can be repaired.
Fire department paging was unaffected and is in normal operation.
Additionally, the wireless communication link to Metamora Police which runs their AICS and Internet services went down during the lightning strike.
Further updates will be posted when information is available.