Instruction manual

6.2 RS232C INTERFACE:
The basic principle of RS232C operation is achieved by 3-wire interface. The
3-wire interface comprises of transmit pin (abbreviated as TXD), receive pin (abbre-
viated as RXD) and a common ground pin (GND). TXD pin of host is connected to
the RXD pin of the instrument and the RXD pin of the host is connected to the TXD
pin of the instrument and the third line connects the GROUNDs of the two sides. I.e.
the TXD and RXD lines are cross-connected to the Host controller.
Hardware HANDSHAKE lines are not used.
The RS232 communications is based on the SEND and RECEIVE signals
only. It does not provide the handshaking protocol. The instrument is designed to
receive all data without missing any of them with the baud rate specified. Standard
baud rate being 9600. The host or the controller (Central Computer) should take
care to read the data at the same speed of the instrument as defined by the baud
rate. The following communication parameters are FIXED for this particular instru-
ment when operating in the RS232C mode. :
POWER ON BAUD RATE 9600 BAUD
CHARACTER LENGTH 8 BITS
STOP BITS 1 BIT
PARITY NO PARITY
HANDSHAKING NO HANDSHAKING
6.3 RS232C Operation
The default communication parameters for RS232C are as follows:
1) BAUD RATE:
The default baud rate is 9600 Baud.
At present the provision for changing the baud rate in LOCAL mode is not available.
2) CHARACTER LENGTH:
The character length is 8 BITS. This is also fixed and cannot be changed by instru-
ment commands.
3) STOP BITS:
The instrument generates 1 stop BIT after each character transmission and checks
for the same during reception. This parameter is also fixed.
4) PARITY:
No PARITY checking is provided. This default configuration is also fixed.
5) HANDSHAKING:
No HANDSHAKING is provided. So the host can send all the data at the defined baud
rate. And at the same time it should be ready to receive the data or response without
any delay.
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