RS232,TTY,RS485 750-650,651,653
:$*2
Ç
,
2
Ç
6<67(0
7
The PLC is able to control transmission and reception of data by means of the control
byte and the status byte.
Initialization of the module:
•
set IR in the control byte
•
transmit/receive functions are blocked
•
output/input buffers are erased
•
serial interface module will load its configuration data
Transmitting data:
•
TR
≠
TA: put characters into output byte 0 to 2
•
amount of characters is specified in OL0 to OL2
•
TR is inverted and read out
•
characters are put into output buffer if TR=TA
Receiving data:
•
RR
≠
RA: in input byte 0 to 2 characters are available
•
amount of characters is specified in IL0 to IL2
•
charactersin IL0 to IL2 are read out
•
RA is inverted and read out
•
all characters are read when RR=RA
The transmitting and receiving of data can be done simultaneously. The initialization
request has prioirity and will stop transmitting and receiving of data immediately.
Message: input buffer full (Bit 3)
Input buffer is full. Data which are received now are lost.