UG-001 Daniels P25 Radio Systems
www.danelec.com
Chapter 6: Radio System Components
37
User
Guide
Channel Selection
Daniels P25 radio modules are capable of 16 channel operation in 2 banks (32 channels total). The
16 channels are controlled via 4 CSEL signal lines connected to each receiver and transmitter module.
The CSEL signal lines are set as either a 0 (0 Vdc) or a 1 (+9.5 Vdc). Table 6-1 shows the channel
selected for the CSEL input settings.
Table 6-1: Channel Selection Settings
Channel Decimal CSEL3 CSEL2 CSEL1 CSEL0
100000
210001
320010
430011
540100
650101
760110
870111
981000
1091001
11101010
12111011
13121100
14131101
15141110
16151111
The Receiver and Transmitter Bank A/B select lines normally fl oat high (+5V), selecting Bank A, but
may be pulled low or high externally via the Bank A/B select line. The Receiver Bank A/B select line
uses the same line as the MT-3 Receiver ISO COR K and the Transmitter Bank A/B select line uses the
same line as the MT-3 Transmitter Standby.
There are 3 different ways to change the channel of a transmitter / receiver module:
1 The user can set jumpers mounted on the motherboard for each Channel Select signal line (Set
of four for each Tx / Rx module). These jumpers can be used to permanently set a subrack slot
at a specifi c channel.
- Jumpers can be set for 0 (0 Vdc) “down” or 1 (9.5 Vdc) “up”
- Pull-up resistor jumpers to 9.5 Vdc must be installed
- These jumpers are read right to left (MSD to LSD)
2 CSEL signal lines can be controlled externally by a tone remote adapter, a CI-RC-4M multiple link
controller, or other third part devices.
3 16 position rotary select switches mounted on the front of the base controller can control the
CSEL lines, and optionally the CI-RC-4L repeater controller can have a rotary switch added.
The Pull-up resistor jumpers to 9.5 Vdc must be removed and all channel select jumpers must be
installed in the 1 or “up” position for both external control and rotary switch control of channel selection.
The locations of the channel select and pull-up jumpers are shown in Figure 6-3.