Watlow MLS - Manual (Page 125)

Troubleshooting
MLS User’s Guide 113
Checking Computer Supervised Systems
These four elements must work properly in a computer-supervised
system:
• The MLS.
• The computer and its RS-232 or RS-485 serial interface.
• The RS-232 or RS-485 communication lines.
• The computer software.
For MLS troubleshooting, disconnect the communications line from the
computer and follow the troubleshooting steps in the first section of this
chapter. The next few sections explain troubleshooting for the other
elements of computer supervised systems.
Computer Problems
If you suspect computer problems, run ANASOFT in Edit mode to find
out if the computer works correctly. (See the ANASOFT User's Guide
for a description of correct operation.)
• If ANASOFT tells you that your computer is not functioning, contact
your computer service representative.
• Check your ANAINSTL program to make sure that ANASOFT and
the MLS are set for the same serial communications port. ANA-
SOFT can use either COM1 or COM2.
• Make sure that you have set the same error checking method--either
BCC or CRC--in ANASOFT and in the processor module.
• Check that the communications baud rate is also set to the same
value--either 2400 or 9600--in ANASOFT and in the processor
module.
• Make sure you are using DOS 5.0 or a later version of DOS.
Serial Interface Problems
Set the serial interface according to the manufacturer's instructions. To
test an RS-232 interface, buy an RS-232 troubleshooter from Radio
Shack. Attach the troubleshooter between the MLS and the computer.
When ANASOFT sends data to the MLS, the troubleshooter's TX LED
should blink. When it receives data from the MLS, the RX LED should
blink.