Watlow CAS200 - Manual (Page 89)

CAS200 User’s Guide Chapter 5: Troubleshooting and Reconfiguring
Watlow Anafaze 77
• To test an EIA/TIA-232 interface, purchase an EIA/
TIA-232 tester with LED indicators. Attach the tester
between the scanner and the computer. When the
computer sends data to the scanner, the tester’s TX
LED should blink. When the computer receives data
from the scanner, the RX LED should blink.
• You can also connect an oscilloscope to the transmit or
receive line to see whether data is being sent or
received. If the serial port does not appear to be
working, the software setup may need to be modified
or the hardware may need to be repaired or replaced.
Communications
Most communications problems are due to incorrect wiring
or incorrectly set communications parameters. Therefore,
when there is a problem, check the wiring and
communications settings first. Verify the following:
• Communications port: Software must be configured to
use the communications port to which the scanner is
connected.
• Software protocol: Set the scanner to MOD (Modbus)
for WatView, ANA (Anafaze) for ANASCAN.
• Scanner address: Configure software to look for the
scanner at the correct address. In a multiple-scanner
installation, each scanner must have a unique
address.
• Baud rate: Software and scanner must be set the
same.
• Error checking (ANA protocol only): Software and
scanner must be set the same (CRC or BCC).
• Hardware protocol: PC and scanner must use the
same protocol, or a converter must be used. The
scanner is typically configured for EIA/TIA-232 when
it is shipped. See Changing Communications on page
81 to change between EIA/TIA-232 and EIA/TIA-485.
To communicate with more than one scanner, or when
more than 50 feet of cable is required, use EIA/TIA-
485. Even for a single scanner, you may use EIA/TIA-
485 and an optically isolating converter to eliminate
ground channels.
• Converter: Make sure that the EIA/TIA-232-to-485
converter is powered, configured and wired correctly.
• Cables: Check continuity by placing a resistor across
each pair of wires and measuring the resistance with
an ohmmeter at the other end.