LG GLOFA-GM Series User Manual page 126

Chapter 7 Communication function
Output Data type
ERR BOOL
STATUS USINT
Remark
[Note 1] If '_Udata_SEND' is used for FNAM specifying frame name in SND_MSG Function Block, the data
specified in SD1,SD2,SD3,SD4 only are transmitted directly irrelevant to the frame list downloaded to
Cnet I/F module. This function is used to transmit all the frames to be sent as written in PLC program,
especially to transmit frames prepared in PLC program for the protocol which is hard to write via Frame
Editor. If '_Udata_SEND' is used, no procedure to write and download frame via Frame Editor is
required.
2) Receiving Function Block : RCV_MSG(Send Message)
Figure on the right shows receiving Function Block, RCV_MSG, to receive
frames composed for receiving. The received data via specified channel of
Cnet I/F module can be received to areas of RD1 ~ RD4. The same frame
name in 'FNAM' area in the Function Block must be downloaded to Cnet I/F
module prior to execution of the receive Function Block. In addition, if ARRAY
variables are used in Frame Editor, the same number of RDx shall be set as
the number of ARRAY variables. Differently from transmission, receiving
Function Blocks need setting with names and structures also as
distinguishable from each other. For receiving, the received data is saved in
RD area only if the received frame is identical with the registered frame when
compared. if several frames of an identical structure are defined, the data is
received via the receiving frame registered foremost and the data will not be
received via the frame registered behind.
Turned On when the Function Block is called but not executed successfully and
keeps On until re-called. If error occurs, error information is displayed on output
STATUS
If ERR is 1 as the result of execution of Function Block, error code is output by
identification code for the error. If ERR is vanished, STATUS is also vanished to 0.
For details of error codes, refer to [Table 7.4] Error codes in user defined Function
Block.
7-7
Description