40
TH1941
‘
s serial port uses the transmit (TXD), receive (RXD), and signal ground (GND) lines of the
RS232 standard. It does not use the hardware handshaking lines CTS and RTS. TH1941 only uses the
smallest subset of the RS232C standard, the signal are listed in Table 5-2.
Function
Code
9 Pin Connector Pin Number
Transmitted Data
TXD
3
Received Data
RXD
2
Signal Ground Common
GND
5
Figure 5-1 shows the rear panel connector for the RS232 interface.
Figure 5-1 Rear Panel RS232 Interface
Connection between TH1941 and a computer shown as Figure 5-2:
DTR(4)
DSR(6)
RXD(2)
TXD(3)
GND(5)
RTS(7)
CTS(8)
(2) RXD
(3) TXD
(5) GND
TH1951
Computer
Figure 5-2 RS-232 Connection Sketch
There may be some difference between TH1941 RS232 interface and a standard RS232C interface. You
can make the connection cable by yourself according the diagram or order one from our company.
Note:
Pin 4 and 6, pin 7 and 8 are shorted respectively at the end of controller.
5.2.2 Sending and receiving data
Model TH1941 transfers data using 8 data bits, 1 stop bit, and no parity. Each program message that is
transmitted to the controller is terminated with <LF> or <CR>.
Table 5-2 Signal Definition for 9 Pin Connector
