Analog Way Scan Vision VHX II - VHX480 - Manual (Page 12)

Chapter 7 : RS-232 PROGRAMMER'S GUIDE SCAN VISION VHX II ™
PAGE 12
Chapter 7 : RS-232 PROGRAMMER'S GUIDE
7-1. INTRODUCTION
If you need to use your own Software Control program from a PC, or WORKSTATION with an RS-232 port, the
SCAN VISION VHX II
™ allows communicating through an ASCII code protocol.
The SCAN VISION VHX II ™ treats any character received on its RS-232 as a possible command but, it only accepts
legal commands. There is no starting/ending in a command string.
A command is 1 character typed on a keyboard and does not require any special characters before or after it. (it is not
necessary to press "ENTER" on the keyboard). A command can be preceded by a value (see chapter 7-2. COMMANDS
STRUCTURE).
When the SCAN VISION VHX II ™ receives a valid command, it will execute the command. Then it will send back the
status of all the parameters that have changed due to this command from the control device.
If the command cannot be executed (value out of range,...), the SCAN VISION VHX II ™ just send back the current
status of the corresponding parameters.
If the command is invalid, an error response will be returned to the controlling device. All responses sent to the
controlling device end with a carriage return and a line feed signaling the end of the response character
string. (see chapter 7-3. ERROR RESPONSES).
7-2. COMMANDS STRUCTURE
Commands are usually composed of a numerical value followed by the command character. The characters used
without any numerical value return the current setting of the command.
COMMANDS structure = VALUE (optional) + CHARACTER.
Examples:
COMMAND
VALUE CHARACTER
RESPONSE DESCRIPTION
none F TSY3 Read the input format.
10 H VPOS10 Set Vertical position to 10.
7-3. ERROR RESPONSES
When the SCAN VISION VHX II ™ receives from the controlling device an invalid command or value, it returns an
error response:
COMMAND
VALUE CHARACTER
RESPONSE DESCRIPTION
none Z E10 Invalid command.
70260 H E13 Invalid value.