INFICON SRT-422 Crucible Indexer - Manual (Page 53)

Computer Interfacing Page 51
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Section 4
Computer Interfacing
The Source Indexer can be connected to a computer or system controller through its
standard RS-232 interface. A simple ASCII protocol is used to send data or commands to, or
to read data from the SRT. This section will describe this protocol and the command set and
the cabling required for operation with a PC.
RS-232 Interface
Section 4.1: RS-232 Description
RS-232 is an electrical specification for the transmission of data in a serial format. It
defines and establishes the electrical compatibility of the communication link between two
pieces of RS-232 equipped instruments. In addition to this RS-232 link a language of
communication and a command set must be defined. Since most every piece of equipment
has different data requirements, more often than not, the commands and the protocol to
communicate to an instrument are unique.
Like the manual use of the Indexer, the RS-232 command set and protocol of the unit
are simple and straightforward.
Section 4.2: Baud Rates And Cabling
After the proper cable connections are made, the baud rate of the computer and the
SRT should be checked or set so that they are set the same.
Section 4.3: Setting The computer Baud Rate
If required, change the baud rate on your computer to the same baud rate as the SRT.
The SRT is shipped from the factory set at 9600 baud. To set a PC to the 9600 baud rate,
type in the DOS command:
Mode Com1:9600,N,8,1 <Enter>
This will set the PC for 9600 baud, no parity, 8 data bits, and 1 stop bit on its COM1
port. It is important to use 8 data bits because the protocol uses all of them. This assumes the
SRT is cabled to COM1 of the PC type computer.