50
TM8000 Encryption
Midian Encryption Programming and Service Manual
June 2006 © Tait Electronics Limited
Signal levels and pin assignments
External Connector (SK1) 15way D Range Socket
13
IOP_GPI05
Programmable Port, CS 2
Digital
3.3 V
CMOS
14
IOP_GPI06
Programmable Port, CS 3/wakeup/indicator Digital
3.3 V
CMOS
15
IOP_GPI07
Programmable Port, CS 4/wakeup/indicator Digital
3.3 V
CMOS
16
DGND
Digital ground
Ground
17
IOP_RXD
Asynchronous serial port - receive data
Digital
3.3 V
CMOS
18
IOP_TXD
Asynchronous serial port - Transmit data
Digital
3.3 V
CMOS
Function
Mode Name Pin
Module
TM8000 Radio
Power Supply
V+
1
5V regulated
Reset
I/P
RS
2
Active low
Resets when supply below 4.75V
Tx pressel
I/P
PTT
3
Active low
CMOS
Busy
I/P
RX
4
Active low
CMOS
Mode
I/P
MO
5
Active low
Momentary or level sensitive
Data to Scrambler
I/P
D-SC
6
Hardwired module
programming I/P
If required
Data to Radio
O/P
D-RA
7
Hardwired module
programming O/P
If required
Mode Indicator
O/P
IND
8
Active high
3mA into LED
Emergency
I/P
EMG
9
Active Low
Module pull-up to 5V
Code select 8
I/P
CS8
10
Active Low
Module pull-up to 5V
Code select 4
I/P
CS4
11
Active Low
Module pull-up to 5V
Code select 2
I/P
CS2
12
Active Low
Module pull-up to 5V
Code select 1
I/P
CS1
13
Active Low
Module pull-up to 5V
Ground
Gnd
14
Transmitter to scrambler I/P
TX-SC 15
AC coupled to 250Hz
200 mV p-p at 1kHz for 2/3 max dev
Scrambler to transmitter O/P
SC-TX 16
DC coupled
Approx. unity thru gain
Receiver to scrambler
I/P
RX-SC 17
AC coupled to 250Hz
650 mV p-p at 1kHz for 2/3 max dev
Scrambler to receiver
O/P
SC-RX 18
DC coupled
Approx. unity thru gain
Audio alert
O/P
AL
19
DC Coupled
Trunking delay
I/P
TRK
20
Provision for future
Pin
Signal
Description
Signal Type Levels
Conditions
1
RX_MUTE
Comparator OP amp output from RSSI line
Digital
0 - 5 V
2
AUX_MIC_IN
Auxiliary microphone input (electret bias)
Analogue
7.5 mV
3.0 V Bias
3
RX_AUD
Receive audio output post Vol, AC coupled
Analogue
1.0 Vp-p
100 ohms
4
+5V
+ 5 Volts regulated
DC
5V
5
RSSI / Ext PTT
Analogue RSSI output / optional PTT input
Analogue
.5-2.5 Vdc
1000 ohms
6
D_RA
Programe out (Data to Radio)
Digital
5 V
7
D_SC
Programe in (Data to Scrambler)
Digital
5 V
8
IND
Module indicator output
Digital
Active high 3mA out
9
IOP_RXD
Asynchronous serial port - receive data
Digital
3.3 V
CMOS
