Metrohm 719 S Titrino - Manual (Page 103)

3.3 Properties of the RS 232 Interface
719 S Titrino
99
3.3.2 Pin Assignment
RS232C Interface
Transmitted Data (TxD).
If no data are transmitted, the line is held in the “ON” condition. Data
will only be sent when CTS and DSR are in the ”ON” condition and
DCD is in the "OFF" condition.
Received Data (RxD)
Data are received only when DCD is "ON".
Request to Send (RTS)
ON condition: Titrino is ready to send data.
Clear to Send (CTS)
ON condition: Remote station is ready to receive data.
Data Set Ready (DSR)
ON: Condition: The transmission line is connected.
Signal ground (GND)
Data Carrier Detect (DCD)
ON condition: The level of the received signal is within the tolerance
range (remote station is ready to send data).
Data Terminal Ready (DTR)
ON condition: Instrument is ready to receive data.
Protective earthing
Direct connection from cable plug to the protective ground of the instrument.
Polarity allocation of the signals
- Data lines (TxD, RxD)
voltage negative (<-3 V): signal state ”ON”
voltage positive (>+3 V): signal state ”ZERO”
- control or message lines (CTS, DSR, DCD, RTS, DTR)
voltage negative (<-3 V): OFF state
voltage positive (>+3 V): ON state
In the transitional range from +3 V to -3 V the signal state is undefined.
Driver 14C88 according to EIA RS 232C specification
Receiver 14C89 " "
E 20
Data Terminal Ready
E 7
Signal Ground
E 5
Clear To Send
E 4
Request To Send
E 3
Received Data
E 2
Transmitted Data
E 6
Data Set Ready
E 8
Data Carrier Detect