Structure of input and output data:
The module is a combined analog input and output module with 2 x 16 bit input and output data. The transfer of the data to be transmitted and the received data is made via up to 3 output and 3 input bytes. One control byte and one status byte are used to control the floating data.
Requests are indicated by a change of a bit. An assigned bit indicates execution by adopting the value of the request bit.
Up to 3 characters which have been received via interface can be stored in the input bytes 0 to 2. The output bytes will contain the characters to be sent.
The control byte consists of the following bits:
Bit 7
0
Con- stant value must always be 0.
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| Control Byte | |
Bit 6 | Bit 5 | Bit 4 |
| Bit 3 |
OL2 | OL1 | OL0 |
| 0 |
Frames available in output |
| Constant | ||
area, OL2 is always 0. |
| value must | ||
eg. OL2, OL1, OL0 = 0,1,1 |
| always be 0. | ||
3 characters should be sent |
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and put into the output. |
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Bit 2
IR
Initialization request
Bit 1
RA
Reception acknow- ledgement
Bit 0
TR
Trans- mission request
The status byte consists of the following bits:
Bit 7
0
Con- stant value must always be 0.
Bit 6 | Bit 5 | Bit 4 |
IL2 | IL1 | IL0 |
Frames available in input area, IL2 is always 0. eg. IL2,IL1,IL0 = 0,1,0
2 characters were received and reside in input 0 and input 1.
Status Byte
Bit 3
BUF_F
Input buffer is full.
Bit 2
IA
Initialization acknow- ledgement
Bit 1
RR
Reception request
Bit 0
TA
Trans- mission acknow- ledgement
RS232,TTY,RS485 |
| 6 |
