Intermec EasyCoder 501 - RS-422;485 Interface Board Troubles; Sensor Kit Troubles; Serial Interface Board Troubles

219Intermec EasyCoder 501 – Service Manual Ed. 7
Chapter 26 Troubleshooting
26.12 Sensor Kit Trou-
bles
• Check that the program reads SYSVAR(12) and/or
SYSVAR(13), see Intermec Fingerprint v6.14, Reference
Manual.
• Check that the sensors are free from dust and foreign objects so
they can read the gaps in the code discs of the ribbon supply and
media supply units.
• Check that the ribbon low sensor is connected to P-605 and the
media low sensor is connected to P-602 on the CPU board and
that the cables are undamaged.
• First, see “No communication (general)”, Chapter 26.2.
• In case of no communication on "uart3:", check that the strap
that selects RS-232 or 20 mA current loop is correctly fi tted:
P-3 pin 1–2 selects RS-232.
P-3, pin 2–3 selects 20 mA current loop.
• Check that the cable to P-4 on the CPU board is properly
mounted.
• If current loop is to be used on "uart3:", make sure that the two
optocouplers in sockets IC-5 and IC-6 are mounted correctly.
• Check that the supply voltage +5V is present.
• If the printer has to supply +5V to "uart3:", check that a jumper
is fi tted on P-6.
• Verify, by means of an oscilloscope, that all signals during
receiving and transmitting data have the appearance described
in Chapter 20. Verify also that oscillator Y-1 on the Serial Inter-
face Board is running.
• First, see “No communication (general)”, Chapter 26.2.
• In case of "uart2:" (RS-422 or RS-485), check that the straps on
P-3 and P-7 to P-11 correspond to the selected protocol and to
the confi guration of the host computer.
• In case of RS-485 on "uart2:" carefully examine the program
and the printer’s setup. Refer to Intermec Fingerprint v6.13,
Programmer’s Guide.
• Check the polarity of the wires in the RS-422 or RS-485 cable.
• If the printer has to supply +5V to "uart3:", check that a jumper
is fi tted on P-6.
• Check that the cable to P-4 on the CPU board is properly
mounted.
• Check that the supply voltage +5V is present.
• Using an oscilloscope, verify that all signals during receiving
and transmitting data have the appearance described in
Chapter 21. Verify also that oscillator Y-1 on the RS-422/485
Interface Board is running.
26.13 Serial Interface
Board Troubles
26.14 RS-422/485
Interface Board Trou-
bles