Cooper Instruments & Systems DFI 1650 Multi-Channel Digital Force Indicator - Manual (Page 10)

CF 126 7 Nov 2001
pin 4)
6 DSR RS-232 Data Set Ready Output 7
7 GND RS-232/RS-485 reference Reference -
8 DCD RS-232 Data Carrier Detect (not
connected)
N/A N/A
20 DTR RS-232 Data Terminal Ready (not
connected)
N/A N/C
22 RI RS-232 Ring Indicator (not connected) N/A N/C
The RS-232 communications pins are electrically isolated from the rest of the instrument.
The RS-232 and RS-485 interfaces are exclusive; an instrument cannot have both.
4.3 Operation Notes
If the DTE wishes to send a command to the instrument, it should first wait for the DSR line (pin 6) to be
high. Then, the DTE can send the command string (which starts with the '#' character and ends in a
Carriage Return). See "Command Format" for further information.
If the address sent by the DTE matches the address of the instrument and the command string is valid,
then the instrument pulls the DSR line low to indicate that it is busy processing the command string. After
the instrument has finished processing the command string, it will pull the DSR line high (to indicate that
new commands will be accepted) and will send the response.
4.4 Typical Wiring Diagrams
Most computers are equipped with either a standard 25-pin male or an IBM 9-pin male RS-232 serial
connector.
Remember that all personal computer serial ports have male connectors! ~ Parallel printer ports have
female connectors. In nearly all situations, a gender changer device is not required!
Model DFI Computer or Terminal
DB 25 connector DB-25 connector
DCE DTE
Figure 4-1: Wiring to 25-pin DTE