Campbell CR800 Series, Руководство оператора

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Section 10. Troubleshooting
476
• Check all analog inputs to make sure they are not greater than ±5 Vdc by
measuring the voltage between the input and a G terminal. Do this with
a multi-meter
(p. 505).
• Check for condensation, which can sometimes cause leakage from a 12
Vdc source terminal into other places.
•
Check for a lose ground wire on a sensor powered from a 12V or SW12
terminal.
• If a multimeter is not available, disconnect sensors, one at a time, that
require power from 9 to 16 Vdc. If measurements return to normal, you
have found the cause.
10.8 Troubleshooting — Communications
10.8.1 RS-232
With newer system, USB enumeration can be a big problem. For example, if
your PC is supporting three external screens, a keyboard, a mouse, and other USB
connections, such as your datalogger connection, on a USB expansion box, the set
up is rife with potential for enumeration mishaps. The best way to resolve a USB
problem with a datalogger connection is to remove as many USB devices as
possible, completely power down the system (disconnect the system from AC
power and UPS devices, then power the system back up, then connect the
datalogger, check that it is working with the support software, then reconnect all
other devices one by one.
On system using nine-pin serial connections, a simple way to test a PC serial port
is to physically connect pin 2 on the serial port with pin 3. This connects the
transmit to the receive. Using a terminal emulator, you should be able to type a
character on the PC keyboard and have it show up on the terminal emulator
screen. If it does not show up, you either have the wrong com port selected in the
terminal emulator set up, or there may be some other program commandeering the
serial port.
Baud rate mis-match between the CR800 and datalogger support software
(p. 86)
is
often the cause of communication problems. By default, CR800 baud rate auto-
adjusts to match that of the software. However, settings changed in the CR800 to
accommodate a specific RS-232 device, such as a smart sensor, display or
modem, may confine the RS-232 port to a single baud rate. If the baud rate can
be guessed at and entered into support software parameters, communications may
be established. Once communications are established, CR800 baud rate settings
can be changed. Clues as to what the baud rate may be set at can be found by
analyzing current and previous CR800 programs for the SerialOpen() instruction,
since
SerialOpen()
specifies a baud rate. Documentation provided by the
manufacturer of the previous RS-232 device may also hint at the baud rate.
10.8.2 Communicating with Multiple PCs
The CR800 can communicate with multiple PCs simultaneously. For example,
the CR800 may be a node of an internet PakBus network communicating with a