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Press the Menu button to enter the menu options to select the Utility option to enter the utility settings interface,
and then select I/O config to enter the port configuration interface. Select the RS232 option to configure RS232
communication.
Select the Baudrate option to set the baud rate.
Select Data bits to select the data bits.
Parity: select the check mode. There is no check bit by default.
Stop bits: set the stop bit, default 1 bit.
(5) Software Protocol
Since the hardware communication check is not used in the RS-232C interface, the multimeter uses the character
return method to reduce the possibility of data loss or data error in the communication. Please refer to the
following when compiling computer communication software:
1. For command syntax and format, refer to Chapter 6 Command Reference.
2. The controller transmits the command using the ASCII code with <LF> as the terminal character. TH1963
executes the command after the terminal character is received.
3. The character received by instrument will be sent back to the controller again. The controller will not send
the next character until the last returned character is received correctly from the instrument. If the controller
fails to receive the character sent back from the instrument, the possible reasons are listed as follows:
The serial interface is not connected correctly.
Check if the instrument has opened the RS232 interface function and the baud rate is selected correctly.
When the instrument is busy with executing a bus command, it will not accept any character from the
serial interface at the same time. So the character sent by controller will be ignored. In order to make
sure the whole command is sent and received correctly, the character without a return character should
be sent again by the controller.
4. The instrument only sends information under following two conditions.
When a character is received normally, TH1953/63 will send the character back as a handshake.
When a query command is received, TH1953/63 will send the query response information.
5. Once a query command is received, TH1953/63 will send the query response information immediately even
if the rest commands have not been finished. So if the command includes two queries, the controller should
read the query responses twice. One query is recommended to be included in a single command.
6. A query response is sent out in ASCII codes with the preset terminal character.
7. Several query responses will be sent continuously with 1ms interval. The controller should be ready to
receive the responses; otherwise the response information will be lost.
8. The controller should receive the query response terminal character. Otherwise you will confuse a terminal
character with a returned character. At the same time the controller should receive the last returned character
before receiving a query response.
9. For some commands that will take a long time to execute, for example reset command, the controller should
keep waiting to avoid the next command being lost when TH1953/63 is executing the former command.
10. Communication software compiled with DOS application software should run under the pure DOS
environment supporting serial port. If it is running under WINDOWS, it may cause errors due to different
management methods of serial port.
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