Message Format - Mitsubishi Electric CR800 Series Ethernet Function Instruction Manual

3.5.6. Message Format

The following section describes the SLMP message format.
3.5.6.1. Request Message
The following is the format of a request message sent from an external device to an SLMP-compatible device.
 Header
This is the header for TCP/IP or UDP/IP. The header is added by the external device before transmission. Note that
the header is normally added automatically by the external device.
 Subheader
This will differ depending on whether a serial No. is added.
The serial No. is an arbitrary number for message recognition added at the external device. When a serial No. is
added and a request message sent, the same serial No. is added to the response message. Serial Nos. are used
when multiple request messages are sent from an external device to the same SLMP-compatible device.
When adding a serial No. to the request message
(When the serial No. is 1234H)
(Fixed value)
ASCII code
(Fixed value)
Binary code
 Use and manage serial Nos. at the external device side.
 When transmitting the message in ASCII code, the serial No. is stored in the order from higher-order byte to
lower-order byte.
 When transmitting the message in binary code, the serial No. is stored in the order from lower-order byte to
higher-order byte.
(Fixed value)
Serial No.
(Fixed value)
Serial No.
When not adding a serial No. to the request message
(Fixed value)
ASCII code
(Fixed value)
Binary code
3 Description of functions
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