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KAHN INSTRUMENTS, INC.
885 Wells Road, Wethersfield, CT 06109
Tel: 860-529-8643; Fax: 860-529-1895
E-mail: [email protected]
www.kahn.com
4.5.2 Digital Interface
The monitor unit features, as standard, an RS-232 interface. An RS-485 interface is
optional. Refer to Section 7.1.
The 9 pin "D" type socket connector on the monitor unit rear panel marked “RS 232” has
the following pin connections :
Pin
Number
Function
1
N/C
2
Transmit data
(TXD)
3
Receive data
(RXD)
4
N/C
5
Signal Ground
(GND)
6
N/C
7
Clear to send (CTS)
8
Request to send
(RTS)
9
N/C
The serial link has the following protocol:-
9600 baud rate
8 data bits
1 stop bit
No parity.
The following parameters may be read via the RS232 interface :
•
Dewpoint (
°
C)
•
Dewpoint (
°
F)
•
Water Content (PPM(V))
•
Water Content in SF
6
(PPM(W))
•
Water Content (g/m
3
)
•
Water Content (g/kg)
•
Pressure (KPa)
•
Relative Humidity (%RH)
•
Temperature (
°
C)
•
Temperature (
°
F)
To initiate data transfer from the S4000 instrument, a request command is required.
