Data Exchange with the SM 335
3-6
SM 335 – High-Speed Analog Input/Output Module for the SIMATIC S7-300
6ES7 335-7HG00-8BA1
Table 3-2
Meaning of the bits in the SM 335 return code
Bit
Description
7
= 1: SM 335 is in “Measuring Only” or “Comparator” mode
= 0: SM 335 is in “Conditional Cycle” or “Free Cycle” mode
6
1)
= 1: “Measuring Only” mode is activated / was last activated
5
1)
= 1: “Comparator” mode is activated / was last activated
4
= 1: Mode cannot be activated. Reason:
•
The “Comparator” mode cannot be activated when “Measuring Only” mode
is enabled.
•
The “Measuring Only” mode cannot be activated when the “Comparator”
mode is enabled or when the “Measuring Only” mode is already active.
3
= 1: The measured value from the analog inputs is not current
(for “Comparator” mode only – with Comparator 2, see Subsection 5.2.1,
Principle of special “Comparator” mode)
2, 1, 0
Error code see Table 3-3
1)
Only bit 5 or 6 can be set but not both
Table 3-3
Description of Bits 0, 1, 2 in the Return Code of the SM 335
Bit2
Bit1
Bit0
Description
0
0
0
No error
0
0
1
Parameter for operating mode ‘Comparator’ faulty
(no analog input designated as comparator input).
0
1
0
Analog input to be used for measuring is disabled.
0
1
1
Error detected at the analog input assigned to the comparator while
‘Comparator’ mode was in force.
1
0
0
Operating mode exited. Reason:
•
Comparator: Comparator time expired (see Subsection 5.2.2)
•
Measuring Only (see Section 5.3 ):
Measurement at one analog input: 60 ms expired.
Measurement at 2, 3 or 4 analog inputs: 40 ms expired.
1
0
1
“Comparator” mode exited because new parameters were transferred
via system function to the SM 335.
