7
◆
Removing the lamps will open the RS-485 circuit and isolate the KMD-5540
from the network.
◆
If one or both lamps are lit, it indicates the network is improperly phased. This
means that the ground potential of the KMD-5540 is not the same as other de-
vices on the network
◆
If the voltage or current on the network exceeds safe levels, the lamps operate as
fuses to protect the KMD-5540 from damage.
Resetting the Controller
If the KMD-5540 appears to be operating incorrectly, or is not responding to com-
mands, you may need to reset it.
Note
Resetting the interface will restore the factory default configuration.
It may be necessary to re-configure the KMD-5540 with HCM to establish normal
communications and operation.
To reset the KMD-5540, proceed as follows.
1.
Remove the screw at the center of the the cover and remove the cover.
2.
Locate the jumper block next to the input pull-up switches (see Illustration 9).
3.
Remove power to the KMD-5540.
4.
Place a short on the RST pins. Use a jumper if a spare is available.
5.
Power up the KMD-5540. Wait until the RDY LED begins to flash normally.
6.
Remove power to the KMD-5540.
7.
Remove the short from the RST jumper.
8.
Reinstall the cover and screw.
9.
Power up the KMD-5540 and re-configure it if necessary.
KMD-5540 CommTalk Protocol Interface Installation & Operation Guide
Operation
Illustration 9—Reset Jumper Block
RESET
JUMPER
