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Gamma Vacuum DIGITEL MPCq Users Manual
Document 900034, Rev B
15. ETHERNET COMMUNICATION
Following protocol are support over Ethernet connection:
Gamma Protocol (Running on TCP port 23)
Modbus TCP Protocol (Running on TCP port 502)
NOTE:
Modbus register map is available on Gamma Vacuum website under download section.
15.1 Gamma Protocol Over Ethernet Connection
Gamma Protocol Command Packet Structure Over Ethernet Connection
A raw TCP session may be established to port TCP 23, allowing remote control. Once the TCP session is established, commands may be
issued.
NOTE:
In comparison to communication over serial connection, no address field and no checksum fields are required.
Table 10. Command Packet Structure Over Ethernet Connection
START
space
COMMAND CODE
space
DATA(optional)
TERMINATOR
3 bytes
1 byte
2 bytes
1 byte
(variable)
1 byte
10.1 Field
10.2 Size
10.3 Comment
1. START
3 ASCII hex characters
ASCII characters are ‘cmd’
Start is the first 3 digits in the command packet and tells controller to start decoding a message.
3. COMMAND CODE
2 ASCII hex characters
Range 00 through FF
See “Table 9. Gamma Protocol Commands” on page 20 for list of available command codes. The command code must be two hex
digits, even if the first digit is a zero.
4. DATA
As needed
ACSII printable characters only
Data field(s) are for any commands that have a data value. Not all commands require data field. If command has more than one data value
associated with it, such as setting an X and a Y value, the command field could be followed by two data fields (X and Y) separated by a
comma and space between them. All data must be sent in ASCII printable format (no binary or “control” characters).
5. TERMINATOR
1 ASCII hex characters
ASCII carriage return
ASCII value of carriage return character placed at the end of a command packet. There is no space before the terminator field.
Gamma Protocol Response Packet Structure Over Ethernet
Connection
In comparison to response structure over serial communication, no
address and no checksum fields are supplied in response.
See response packet structure over serial connection for more
information.
15.2 Examples - Gamma Protocol Over Ethernet
Connection
Example 1
Command - SYS GET MODEL, 0x01
Tx – “cmd 01” + carriage return.
Rx – “OK 00 DIGITEL MPCQ” + carriage return
Example 2
Command - HV GET CURRENT, 0x0A
Tx – “cmd 0A 01” + carriage return
Rx – “OK 00 1.33E-11 AMPS” + carriage return
Example 3
Command - HV GET PRESSURE, 0x0B
Tx – “cmd 0B 01” + carriage return
Rx – “OK 00 1.0E-11 TORR” + carriage return
16. PROFIBUS COMMUNICATION
For Profibus information reference Profibus user manual, document
900033, available on Gamma Vacuum website under download
section.
