Automatic control function programming manual ladder language

15.3.11 «MESSAGE READ» Request
The CNC function sends this request at its own initiative to the automatic control function after instruction «$1» or «$11»
in the part programme being executed.
Two types of messages are sent by the CNC server:
- nonblocking messages «$1 «Message» LF»,
- blocking messages «$11 «Message» Lf».
The automatic control function receives the message sent to it by the monitor on ports 0x10 to 0x17 (axis groups 1
to 8) using the uniti() function.
Request format
Number of bytes
contained in the
«DATA-SPECIFIC» field
Message contained in
the part programme
15 - 28 en-938846/4
REQUEST CODE
(1 byte)
0xFC
OBJECT-ADDRESS
(1 byte)
DATA-SPECIFIC
CATEGORY
(1 byte)
0x06
DATA-LENGTH
(1 byte)
Transmission of a Nonblocking Message
This request does not wait for an answer from the automatic control function. It may however be associated with
another request initiated by the automatic control function which is used to acknowledge the unsolicited data. The
mechanism used to wait for the acknowledgement is described below.
The instruction «Ln = $1» programmed in the part programme is used to retrieve an answer from the automatic control
function.
Transfer mechanism
The message «$1 «Message» LF» is sent once to the automatic control function. The part programme then continues
without waiting for an acknowledgement.
The answer is transmitted by a «WRITE OBJECT» request with segment 224. The value of the object is stored by
the CNC function until it is read by the part programme.
The part programme retrieves this value by function $1 programmed in a parametric expression of the type «Ln = $1».
If no value is sent or if the last value sent was already acknowledged, the part programme goes on wait for a new write
of segment 224.
For read, the CNC sends back the last value sent to it if it is still stored, i.e. if it has not yet been retrieved by the part
programme. Otherwise, it sends the one’s complement of this value.
REMARK An attempt to transfer a message from a part programme to the automatic control
function cancels storage of a previous write of segment 224 on the axis group
considered.