User`s manual

196
• Data communications using user frames
• When designating the last frame, an arbitrary part of data in the area starting from the start of the reception
of the current message until time-out is read into the Q series C24, and the data in the last frame area is
ignored (deleted).
• Stores the error code to the data receive result storage area (buffer memory addresses 258H, 268H) for
the target interface and turns on the reception abnormal detection signal (X4, XB) and waits to receive the
next data.
(c) Data communications using non procedure protocol (Format 1)
The reception monitoring format 1 of the no-reception monitoring time (timer 0) is used for receiving a message
for which the receive complete code and receive data count has not been preset. This occurs when the no-
reception monitoring time (timer 0) runs out on the non procedure protocol.
• Data is received by the Q series C24 until the time is out, the receive data read request signal (X3, XA) turns
ON, and the following data reception waiting condition occurs.
When receiving using the receive data count (Receive data count: 4 bytes)
After 3 bytes of data is received, the 3-byte data is stored in the received data storage area of the buffer
memory by the time out (timer 0) and the receive data read request signal to the programmable controller
CPU turns ON.
(d) Data communications using bidirectional protocol
• Ignores (deletes) the receive data from the start of reception of the current message to time-out.
• Stores the error code to the data receive result storage area (buffer memory addresses 258H, 268H) for the
target interface.
• When the receive data complete, transmits a NAK message to the external device and waits to receive the
next data.
(*1)
*1
CR
(X4/XB)
External device
Q series C24
Abnormal reception detection signal
Timer 0
Set time
CR is treated as 1 byte of data included in the message.
(X3/XA)
CAB
External device
Q series C24
Receive data read request signal
Timer 0
Set time