HEIDENHAIN TNC 306 Technical Manual - Manual (Page 402)

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TNC 416/TNC 406/TNC 306 PLC Modules for TNC 416/406 3/2000
4.2
Read Edges of PLC Inputs (Module 9004)
Module 9004 detects the rising or falling edges of PLC inputs and sets corresponding edge markers
or bits in the specified byte range. Changes to inputs can be detected only if a change has also
been made to the PLC memories.
Constraints:
•
Ensure that the edge markers or bytes are placed in a range which is still free
• The edge bytes are assigned beginning with the LSB in ascending order and rising byte
address; unnecessary bits are deleted.
Possible errors:
•
One of the input parameters is negative.
• The parameter for the edge evaluation is set greater than three.
• The sum of the 1st PLC input and the number of PLC inputs is greater than the
maximum permitted PLC input number (I383).
• The sum of the 1st edge marker and the number of PLC inputs is greater than the
maximum permitted marker number (M3279).
• The sum of the 1st edge byte and the number of bytes required is greater than the
maximum permitted byte number.
Call:
PS B/W/D/K
PS B/W/D/K
PS B/W/D/K
PS B/W/D/K
0: rising edge; entry in edge marker
1: falling edge; entry in edge marker
2: rising edge; entry in edge byte
3: falling edge; entry in edge byte
CM 9004
Error status after call: M3171 =0: Edge markers have been set
=1: See above for error conditions