SATEC SLC500 - Manual (Page 13)

13
5 TROUBLESHOOTING
This chapter describes common problems you might encounter during installation of the
communication driver, and offers suggestions for corrective action.
It is recommended that you apply a sample ladder program discussed in Section 4.4 for testing
the CPU-BASIC module interface operation. With this program you can monitor the data
exchange between the CPU and the BASIC module through the CPU data files.
The CPU doesn't interface to the BASIC module
The symptom indicating the problem is that the address of the instrument being polled that is
located in word 1 in the CPU input data file is still unchanged while you are monitoring the file
with APS software.
To ensure that the BASIC module operates properly, carry out the following procedure:
1. Switch the power supply off.
2. Unplug the network connector from port PRT2.
3. Turn power on.
If on power up, LED PRT2 located on the front panel of the BASIC module doesn't flash, it
could be for one of the following reasons:
1. Incorrect setting of the JW3 jumper.
2. Improper EPROM installa tion.
For information on the jumper setting for jumper JW3, see section 2.1. For additional
information on EPROM location and jumper JW3 pin assignments, refer to the SLC 500
BASIC Module Design and Integration Manual.
If on power up, LED PRT2 flashes three times with short intervals, for about 1/4 of a second,
between flashes, which means that the driver requests the instrument, then the BASIC module
is operating properly and the problem is located in the CPU. Determine whether one of the
following is the cause:
1. Check whether the CPU is in RUN mode.
2. Make sure the I/O configuration settings for the BASIC module slot are correct. Refer to
Section 2.3 for information about configuring I/O for the BASIC module.
3. Check whether your ladder program is correct. If you are using a sample ladder program
provided in Appendix B, make sure that you have accommodated it properly to the slot and
to your data files.
If the handshaking mechanism operates properly, then, while the network cable is
disconnected, LED PRT2 will flash continuously with short intervals between flashes
signifying the driver polls instruments and transmits data to the CPU via the M1 file.