4 troubleshooting, Troubleshooting – Metrohm 781 pH/Ion Meter: Operation via RS-232 User Manual
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4
Troubleshooting
780/781 pH/Ion Meter - Operation via RS232
27
4 Troubleshooting
Problem
Questions for remedical action
No characters can be
received on a
connected printer.
• Are the instruments switched on and cables plugged in
correctly?
• Is the printer set to ”on-line”?
• Are baud rate, data bit and parity the same on both instruments?
• Is the handshake set properly?
If everything seems to be ok, try to print a report with the key
sequence
printed out correctly, check if reports are defined in key
No data transmission
and the display of the
pH/Ion Meter shows
an error message.
• error 42: Transmission error. Is the printer set to "on-line"? Is the
connection cable properly wired?
• error 43: Data output of the pH/Ion Meter disabled for longer
than 6 s by XOFF.
• error 36-39: Receive error. Are the RS settings the same on both
devices?
The received
characters are
garbled.
• Are the RS settings the same on both devices?
• Has the correct printer been selected?
• Data transfer has been interrupted on the hardware side during
the printout of a curve. Re-establish connections and switch
printer off/on.
Wrong line spacing.
The printer does not emulate completely the preset mode. Usually
these problems arise with the IBM mode. Set the printer to a
different mode (e.g. Epson).
Printout of curve is not
ok. Other reports are
printed ok.
Handshake is necessary for the printout of curves.
• Is your cable correctly wired? (The DTR of the printer has to be
connected to the CTS of the pH/Ion Meter.)
• Set "HWs" for the handshake of the pH/Ion Meter. Configure the
printer such that its DTR is set (possibly with DIP switches).