Rs232 Interface - VOLTCRAFT PHT-200 Bedienungsanleitung

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
Centre contact →
External contact →
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
D14
D13
D12+D11
D10
D9
D8 to D1
D0
The RS232 data format is:
Baud rate:
Parity bit:
Data bit number:
Stop bit:
9 pol. Sub-D socket for PC (serial port)
Pin 4
Pin2
A 2.2 KOhm is required between pin 2 and pin 5.
Start symbol
4
When the upper display is sent = 1
When the lower display is sent = 2
Measuring value on the display; °C = 01 // °F = 02 // pH = 05 // mV = 18
Polarity; 0=positive; 1=negative
Decimal point (DP) at the appropriate place (from right to left); 0 = no DP; 1 = 1DP;
2 = 2DP; 3 = 3DP
Reading (D8 = largest digit (MSD), D1 = lowest digit (LSD)). With a display of 1234, the
following bit rate (D8 - D1) results: "00001234"
End signal
9600, N, 8, 1
9600
No parity bit (N)
8
1 stop bit
35