Advanced Troubleshooting Table

Symptom Cause Solution

M/R Scanner power supply shuts off

(Compaq units W/cooling fan only)

Load Resistor Add a 5 watt 25 ohm resistor across #1 & #2 at terminal T2 on the LNP card
Cars appear to skip floors, inputs turn on and off at random etc. Network termination resistors

PC is end of line W/internal serial interface. Solder a 100-120 ohm resistor across the network data B+ and A- at the PC

PC is end of line W/external serial interface (black box – RE Smith). Check for jumper ON at pins J16, J18, and J20 inside black interface box.

M/R Scanner is end of line.  Install jumper J16.  When a jumper is not available connect a 100-120 ohm resistor across #1 & #2 terminal T3 on the LNP card.

  Improper grounding

Verify that all Lift-Net network shields are connected together and grounded in one place only

Model #D-60A power supplies(WO/cooling fan) connect a 100 ohm ½ watt resistor from ground to com on the power supply terminal strip.

  Low input voltage 48 volts or less

W/old style IO96 input cards verify that pin jumpers(located just above the input terminal blocks) are installed at all input terminals in use.

W/new style IO96 input cards (no pin jumpers) read the value of the input resistors (located just above the input terminal blocks).

Low Voltage IO96 boards have 220k resistors (red, red, yel).

High Voltage IO96 boards have 470k resistors (yel, viol, yel).

  Noise suppression

Contact tech support for R-C network placement.

  LNP power supply Check 5 VDC output at the power supply terminals +5V and Com. Adjust for 5.1 VDC with the +5V rheostat.
  Elevaor controller rectifier defective Controllers that use rectified AC to power the relays, can cause erratic Lift-Net operation when the rectifier begins to break down. Locate and replace the defective rectifier.

Controls (relay outputs) don't respond

Connection Relay output plug for relays A-1 to A-8 should be plugged into the first plug on the left of the LNP card. Relays B-1 to B-8 go into the next plug, etc. NOTE: red stripe on the ribbon cable should face UP.
Refer to network termination resistors
  Wiring or configuration Activate the output be clicking on the proper control. Check which relay output LED lights up. Contact Tech Support for output address values.
All car or hall calls display simultaneously seemingly at randomn. Common or ground connection Be certain the common (pin 9) is connected on each car or hall call input plug. Check for proper grounding at the M/R scanner.
One or more inputs are not responding – Low voltage
– High voltage
– Bad IO96 card
– Address jumpers
Refer to Low Voltage correction.
Refer to High Voltage correction.
– Replace bad IO96 input card
– Check for correct placement of address jumpers on the IO and LNP boards. (see graphic) When multiple LNP cards are on the Lift-Net network each LNP must have a different binary address
Refesh All returns zero Bytes Received Hardware or wiring from LNP to Monitoring Computer Check connection from Monitoring Computer to Lift-Net Network.Check data wiring at LN-485 Interface. Wire at LN-485 (+) term connects to LNP T3 pin 1(+). LN-485 (-) term connects to LNP T3 pin 2(-). LN-485 (C) term connects to LNP T2 pin 3 (ground). Check LN-485 power supply is plugged into live outlet.
  Configuration Check that a valid Logical Port is selected. For Lift-Net networks set baud rate to 19200. Set parity EVEN. Set DTR and RTS checked.
No Comm on 1 or more banks Hardware or wiring See Refresh All above
  Address jumpers Check for correct placement of address jumpers on the IO and LNP cards. (see graphic). When multiple LNP cards are on the Lift-Net network, each LNP must have a different address.
  Bad LNP card Replace LNP card. Verify correct address jumper configuration.