Table of Contents
Advertisement
CAP AND USER PROGRAMMABLE CAP
If you have difficulty with your application, the
problem may be in either the unit's configuration
or the cabling between the devices. This chapter
advises you how to quickly find and correct the
problem.
5.1 Diagnostic LEDs
Five diagnostic LEDs are mounted on the front of
the unit. One LED is for POWER. Two LEDs are for
Port A, and two are for Port B. The two LEDs for
each port are Receive Data and Transmit Data. If
the unit does not appear to be communicating with
your devices, the following checklist may be useful.
1.Power — The Power LED should be on when
the unit is plugged into a wall outlet. The unit
will not operate without power.
2.Receive — This indicator flashes when the unit
receives data. The unit cannot pass information
between two devices unless it receives data to
transmit. Never assume your equipment is
transmitting data to the unit. Monitor this LED
to verify that the unit is actually receiving data.
If this LED does not flash when your device is
transmitting to the unit, check the following:
a) Verify whether your device is DTE or DCE.
b) Check that the crossover cable pinning is
correct.
If the LED doesn't flash, another problem might
be that the unit is ignoring the data your device
is sending. This happens if the CAP's receiver is
not enabled, or if the data doesn't have the
same baud rate that you have configured for the
CAP to use. Check the baud rate and DCD input
DIP switch options.
18
5.0 Troubleshooting
3.Transmit — If the CAP receives data when its
receive enable is active, it puts the data in its
internal buffer. Then the CAP attempts to
transmit the data out the other port. However,
the CAP cannot transmit if it is flow-controlled
OFF. If the transmit LED does not light, check
the flow control and the CTS DIP switch
options.
5.2 Cables and Configuration
If the LEDs for both ports are working properly, but
the two devices are not communicating with each
other, check the following:
1.Check for a good connection between Pins 2, 3,
and 7 of the cables that attach your equipment
to the CAP. These are the pins for TXD, RXD,
and Signal Ground.
2.Recheck all DIP switches and jumper positions
for both ports to verify that the CAP is
configured to match both devices it is
connecting. For example, if Port A is configured
to use one stop bit and your device is expecting
two, it may not receive the data correctly.
Advertisement
Table of Contents
