8
Operation
When power is applied to the TrainSpeed unit, it will display
the jumper settings for a short time by displaying oP.x where
‘x’ is the jumper setting shown in table 3.
oP.1
After about 2 seconds, if all is connected correctly, the display
will show Sn.1 indicating that sensor has been detected
correctly.
Sn.1
If the sensor has not been detected correctly you will see the
Sn.E message:
Sn.E
At power-up the unit will scan the sensor pair. It expects both
sensors to be ‘seeing’ light. If either sensor indicates that it is
‘dark’ (common causes can be a train parked over it, the
sensor fell out of the hole or the connector is not installed
correctly) that will cause the Sn.E display. If the missing
sensor pair is uncovered, see the troubleshooting section. If
you had parked a train over the sensor (or left this manual
lying over it) the unit will begin scanning the sensor as soon as
the error condition is corrected, though this display will not
change. If the sensor was detected properly try a test, tripping
the sensors with your finger exactly 1 second apart. The
display should then read 36 if you are using the 1/50 of a mile
sensor spacing (72 for 1/25, 18 for 1/100 and 9 for 1/200). If
