User`s guide

Table Of Contents
Communication
228 Mitsubishi Electric, MA00759F
Right-click on No Protocol Mode and select Properties.
No protocol ctrl. reg.
The first control register used in No protocol mode.
Register Description
Ctrl. reg. 0 Start register for the transmission data buffer.
The first register in the buffer area contains the total number of bytes
to be sent. The following registers contain the data to be sent. The
maximum buffer size is 127 registers = 254 bytes.
Ctrl. reg. 1 Command register for transmission.
Set to 1 by the controller when transmission is requested. Set to 0 by
the operator panel when transmission is completed.
Ctrl. reg. 2 Start register for the reception data buffer.
The first register in the buffer area contains the total number of bytes
received. The following registers contain the received data. The
maximum buffer size is 127 registers = 254 bytes.
Ctrl. reg. 3 Command register for reception.
- Set to 0 by the controller when it is ready to receive.
- Set to 1 by the operator panel when the message is available.
- Set to -1 (FFFF) on error message (e.g. too short).
- Set to 2 by the controller when clearing of the port buffer is required.
- Set to 3 by the operator panel when clearing of the port buffer is com-
pleted.
The port buffer is automatically cleared on start up and when switching
between Transparent mode and No protocol mode, i.e. the register
receives the value 3.
Ctrl. reg. 4 End code (1 or 2 bytes) on the received message.
Ctrl. reg. 5 Length of the received message. If 0, the end code is used.