Metrohm 899 Coulometer - Manual (Page 111)

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10 Appendix
899 Coulometer
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10.8 Remote control via an RS-232 connection
The 899 Coulometer can be remote controlled via an RS-232 connection.
For this, a 6.2148.030 RS-232/USB Box is necessary. Connect the
RS-232/USB Box to the USB interface of the instrument.
The RS-232/USB Box has two connectors for RS-232 instruments. The
RS-232 remote control functions only through the connector RS-232/2.
The connector RS-232/1 is designed for connection with a balance. Con-
nect the RS-232/2 connector of the RS-232/USB Box to a serial interface
(COM interface marked with the symbol IOIOI) of a PC. Use a
6.2134.040 connection cable.
6.2134.040
Figure 29 Connecting the RS-232/USB Box to the PC
Interface parameters
We recommend the following parameters for the RS-232 interface
COM2:
￭ Baud rate: 19200
￭ Data bits: 8
￭ Stop bits: 1
￭ Parity: none
￭ Handshake: software
On the 899 Coulometer, adjust the interface parameters under
Menu
▶ System ▶ External devices ▶ COM2 settings.
Transfer protocol
The data communication is synchronous. On each command there is an
acknowledgement by the instrument.
A command must be sent to the instrument with the control characters
CR LF as terminator. The acknowledgements of the instrument will also
be transferred with CR LF as terminator.
The instrument does not send spontaneous messages.