PlantLinc
PLR5000 User’s Guide
P/N 161-09888-001
DATA-LINC
Group
26
Troubleshooting
“I have two radio modems, one configured as a Master and the other as a Remote. When they are
plugged in, the LEDs indicate they are receiving power, and yet they will not connect. Why not?”
There are several reasons why this may occur:
1. The radio modems are running at full power and are too close to each other. If the radio modems are
within 5-10 feet of each other and will not link, try either reducing the RF power to 0 on each or moving
one unit to another room. (This problem occurred on the initial generation of product with the 555-call
book number prefix. It has been addressed in radio modems with call book numbers 556 and higher).
2. The radio modems are not in each other’s Call Books.
3. The number of the Remote is in the Master’s Call Book, but the Master’s menu is not set to call that
number.
4. The Master is set to Call All and a setting of 000-0000 precedes the number of the radio modem with
which you are trying to communicate.
“I am able to link to a Remote unit within line of sight when the PLR5000 I have is outside. However,
as soon as I walk inside with it I lose the link, even if I place the radio modem by the window which
faces the Remote unit.”
Many modern buildings use energy efficient glass that wreaks havoc on RF signals. This glass contains a
metal film that is very effective in blocking all radio waves. If your situation is as described above, the
preferable solution is to install an antenna outdoors.
“I have several radio modems set up to communicate with each other in a point-to-multipoint mode, yet
they are not establishing contact.”
In a multipoint system, there are two critical parameters, which must be set correctly to establish a
communications link:
1. The Remote’s Call Book must contain the call book number or Network ID of the Master and/or
Repeaters to which it will be communicating.
2. All radios must be set to run at the same RF data rate. Remote modems must match the Masters RF
data rate.
“In bench testing several units in a multipoint system, it appears that they are not communicating
through the multipoint Repeater. When all units are powered, the Remotes’ Carrier Detect lights are
on, indicating a connection, yet when I unplug the Repeater, those Remotes set up to communicate
through that Repeater remain connected.”
In a multipoint system, a Remote will attempt to communicate with any Master or Repeater (which looks like
a Master in a multipoint system) that is in its call book. Therefore, it may be that the Remotes are
communicating with the Repeater when it is powered, and when it is unplugged they are establishing a link
with the Master. To test whether or not this is what is occurring, go into the call book of the Remotes which
are set up to communicate through the Repeater and remove the Master’s call book number. When all units
