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11. RS232 interface
The meter is fitted with a serial interface for exchanging data with a computer. This can be found on the right side
under the lid. The interface is in the form of a 3.5 mm jack plug socket and requires a compatible data cable, which
is an optional extra.
The data cable has the following components:
Jack plug 3.5 mm mono
9 pol. Sub-D socket for PC (serial port)
Centre contact →
Pin 4
External contact →
Pin2
A 2.2 KOhm is required between pin 2 and pin 5.
The serial data signal is made up of 16 Bits in the following order:
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
Each data bit has the following function:
D15
Start symbol
D14
4
D13
When the upper display is sent = 1
When the lower display is sent = 2
D12+D11
Measuring value on the display; °C = 01 // °F = 02 // pH = 05 // mV = 18
D10
Polarity; 0=positive; 1=negative
D9
Decimal point (DP) at the appropriate place (from right to left); 0 = no DP; 1 = 1DP;
2 = 2DP; 3 = 3DP
D8 to D1
Reading (D8 = largest digit (MSD), D1 = lowest digit (LSD)). With a display of 1234, the
following bit rate (D8 - D1) results: “00001234”
D0
End signal
The RS232 data format is: 9600, N, 8, 1
Baud rate:
9600
Parity bit:
No parity bit (N)
Data bit number:
8
Stop bit:
1 stop bit
