24
Installing the Radio
TM8100/TM8200 Installation Guide
© Tait Limited
November 2012
Hardware Links and
Power-Sense
Options
The radio provides four hardware links (LK1 to LK4) on the top-side of the
main board which can be configured to attain different power-sense options.
Table 3.4
shows the configuration of the hardware links LK1, LK2 and LK4
for the individual power-sense options. It also lists the dependence of the
power-sense options with respect to the GPI lines, which can or cannot be
used.
Hardware link LK3 is used for ‘emergency power sense’.
For more information on hardware links and power-sense options refer to
the service manual.
Table 3.4
Configuration of hardware links for power-sense options
Power-sense option
Links
required
Configuration of remaining links and
use of AUX GPI3 and IOP GPIO7
Voltages
required
13.8V battery power
sense
LK1 in
LK2 in:
AUX GPI3 must be left floating.
10.8V
≤
supply
≤
16V
LK2 out:
AUX GPI3 can be used as GPI
1
.
LK4 out
IOP GPIO7 can be used as GPIO.
auxiliary power sense
(ignition sense)
LK2 in
LK1 in:
Input line must sink >1mA from
AUX GPI3 (which is pulled to 13.8V by a
33k
Ω
resistor). The impedance between
the vehicle ignition signal and ground
must be
≤
1k
Ω
.
AUX GPI3
≤
0.7V off
AUX GPI3
≥
2.6V high (active)
ignition-sense tolerant to
3.3V, 5V and 12V
LK1 out:
Input line must be active high
2
.
LK4 out
IOP GPIO7 can be used as GPIO.
internal power sense
LK1 out
IOP GPIO7
≤
0.7V off
IOP GPIO7
≥
2.6V high
(active)
ignition-sense tolerant to
3.3V and 5V only
LK2 out
AUX GPI3 can be used as GPI.
LK4 in
With LK4 in, the input line must be active
high
3
.
no power sense
LK1 out
10.8V
≤
supply
≤
16V
LK2 out
AUX GPI3 can be used as GPI.
LK4 out
IOP GPIO7 can be used as GPIO.
1. If LK2 is out and AUX GPIO is not used, R775 (33k
Ω
) should be placed to ensure that AUX GPI3 does not float
(R775 is not placed by factory default).
2. If LK1 is out and R775 is placed, AUX GPI3 should be driven low as well.
3. If LK 4 is in and R723 is placed, IOP GPIO7 should be driven low as well. (R723 is placed by factory default.)