Supplementary Conditions; Examples; Writing To The Nc I/O - Siemens SINUMERIK 840D sl Function Manual

A4: Digital and analog NC I/O for SINUMERIK 840D sl
2.4 Direct I/O access without PLC
2.4.4

Supplementary conditions

Parallel writing of the NC and PLC
Parallel writing of I/O outputs by the NC via direct access and from the PLC user program
results in a random, mutual overwriting of the output values. The application is therefore not
permitted, but cannot be prevented on the control.
Life beat monitoring
At the start of an interpolator cycle, a check is made for each I/O range whether the sign-of-
life of the associated slot or I/O range has failed. If this is the case, alarm 9050 or 9052 is
displayed.
Effects:
● The part program processing is not stopped.
● When the sign-of-life returns, the alarm is cleared automatically.
2.4.5

Examples

2.4.5.1

Writing to the NC I/O

Requirement
A valid configuration must already have been loaded to the PLC.
Parameterization for part programs / synchronized actions
Specifications
● Parameterization of the 6th data record: Machine data / system variable index = 5
● Configuration data:
– Logical start address = 334
– Slot length = 8 bytes
● Representation: Little endian format
Parameterization in the machine data
● MD10510 $MN_DPIO_LOGIC_ADDRESS_OUT[ 5 ] = 334 (logical start address)
● MD10511 $MN_DPIO_LENGTH_OUT[ 5 ] = 8 (length of the I/O-range in bytes)
● MD10512 $MN_DPIO_ATTRIBUTE_OUT[ 5 ]
– Bit0 = 0 (little endian format)
– Bit1 = 0 (writing only via system variable)
– Bit3 = 0 (issue slot sign-of-life alarms)
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Function Manual, 10/2015, 6FC5397-1BP40-5BA3
Extended Functions