External Control
Application
These specifications cover the communications control of the plasma monitor by external equipment.
Connections
Connections are made as described below.
plasma monitor |
| External equipment | ||||||||
| e.g., Personal computer | |||||||||
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1)Connector on the plasma monitor side: EXTERNAL CONTROL connector.
Type of connector: D-Sub 9-pin male
No. Pin Name
1No Connection
2RXD (Receive data)
3TXD (Transmit data)
4DTR (DTE side ready)
5GND
6DSR (DCE side ready)
7RTS (Ready to send)
8CTS (Clear to send)
9No Connection
1 2 3 4 5
6 7 8 9
Communication Format
8 bit |
| 8 bit |
| 8 bit |
| 8 bit | 8 bit | 8 bit |
| 8 bit |
| 8 bit |
Command 1
Unit ID 1
Unit ID 2
Command 2
Data length
Data
Check sum
Command 1
Command 1, along with command 2, is a number used to distinguish each command.
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.
Unit ID 1 and Unit ID 2
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.
1)Unit ID 1: Indicates the equipment sending the signal
2)Unit ID 2: Indicates the equipment receiving the signal
Command 2
Command 2, along with command 1, is a number used to distinguish each command.
2)Connector on the external equipment side: Serial port
See the specifications of the equipment that is to be connected for the type of connector and the pin assignment.
3)Wiring
Use a crossed (reverse) cable.
Wire the cable so that each pair of data lines cross between the two devices. These data line pairs are RXD (Receive data) and TXD (Transmit data), DTR (DTE side ready) and DSR (DCE side ready), and RTS (Ready to send) and CTS (Clear to send).
Check Sum (CKS), Error Processing, and ACK
1)The check sum described below and
Check Sum Example
DFH | 80H | 60H | 47H | 01H | 01H | 08H |
Command 1 | Unit ID 1 | Unit ID 2 | Command | 2 Data Length | Data | Check Sum |
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Total 208H
Communication Parameters | 2) Error Processing | |||
• | When the communication interval is vacant for more | |||
(1) | Communication system | Asynchronous |
| than 4 ms, thereafter a received Command 1 will be |
(2) | Interface |
| recognized. If, at this time, meaningful data cannot | |
(3) | Baud rate | 9600 bps |
| be recognized, that data will not be recognized (as |
(4) | Data length | 8 bits |
| valid data). |
(5) | Parity | Odd | • | An ACK will not be returned unless the receive data |
(6) | Stop bit | 1 bit |
| error, the check sum error, and the receive data are all |
(7) | Communication code | Hex | 41 | taken in. |
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