PDxx01 | Page: 5 / 49 |
Document Version [1.0]
3. Communication Format
8bit 8bit 8bit 8bit 8bit 8bit
Command 1
Unit ID 1
Unit ID 2
Command 2
Data length
Data
Check sum
8bit 8bit
3-1. Command1
Command 1, along with command 2, is a number used to distinguish each command.
Bit1, Bit0: 11B or 10B :Usually, a form
In the case of ACK, when the lower order 4 bits is FH (as in 3FH and 7FH), this indicates that the commands and data of the supported equipment have been received. When the lower order 4 bits is BH (as in 3BH and 7BH), this indicates that unsupported commands and data have been received.
3-2. Unit ID1,2 (UA1,UA2)
Unit ID 1 and unit ID 2 are numbers used to identify the equipment that is to be connected.
60H is used for the plasma monitor and 80H is used for external control equipment such as a personal computer.
3-3. Command 2
Command 2, along with command 1, is a number used to distinguish each command.
3-4. Check Sum (CKS), Error Processing, and ACK
1)The check sum described below and
Check Sum Example
DFH | 80H | 60H | 47H | 01H | 01H | 08H |
Command1 | Unit ID1 | Unit ID2 | Command2 | Data Length | Data | Check Sum |
|
|
|
|
|
|
|
Total 208H
2)Error Processing
•When the communication interval is vacant for more than 4 ms, thereafter a received Command 1 will be recognized. If, at this time, meaningful data cannot be recognized, that data will not be recognized (as valid data).
•An ACK will not be returned unless the receive data error, the check sum error, and the receive data are all taken in.
Company Restricted