Siemens SIMATIC ET 200S Operating Instructions Manual page 257

Table 4- 4 Assignment of the Control Interface (Outputs)
Address Assignment
Bytes 0 to 3 Comparison value 1 or 2 (double word)
Byte 4 Bit 7: Error acknowledgment EXTF_ACK
Bit 6: Acknowledgment of latch function LATCH_ACK
Bit 5: Reserved = 0
Bit 4: Reserved = 0
Bit 3: Reserved = 0
Bit 2: Reserved = 0
Bit 1: Load comparison value 2, CMP_VAL2
Bit 0: Load comparison value 1, CMP_VAL1
Byte 5 Reserved = 0
Bytes 6 to 7 Reserved = 0
Notes on the Control and Feedback Bits
Bits Notes
CMP Comparison result of comparator 1
CMP2 Comparison result of comparator 2
CMP_VAL1 Load comparison value 1
CMP_VAL2 Load comparison value 2
ERR_24V The encoder supply is short circuited. ERR_24V is reset when the short circuit is eliminated and
acknowledged with the EXTF_ACK control bit.
ERR_LOAD Error while loading the comparison values because both control bits CMP_VAL1 and CMP_VAL2 are set.
ERR_PARA Incorrect parameter assignment for the ET 200S station.
Cause: Total steps of the absolute encoder are not in the range of values for the type of encoder.
The parameter bit is cleared when a correct parameter assignment is transmitted.
ERR_SSI The 1SSI detects an absolute encoder error if the message frames at the SSI interface are faulty.
Causes: No encoder connected; wire break in the encoder cable; over voltage of encoder supply; type of
encoder, transmission rate, parity error, monoflop time do not correspond to the connected encoder;
programmable encoders do not correspond to the settings on the 1SSI; encoder is defective or faults exist.
ERR_SSI is reset when the cause of the error is eliminated and acknowledged with the EXTF_ACK control
bit.
EXTF_ACK Error acknowledgement for the absolute encoder ERR_SSI and encoder supply short circuit ERR_24V
errors
LATCH_ACK Acknowledgement for latch function
LZ This parameter is only active in isochronous mode.
When sign of life is on, the sign-of-life bit is toggled, i.e., the last sent value is inverted, each time an
encoder value is read in in isochronous mode. If a reduction is assigned in the "Encoder Sampling Rate"
parameter, the value is toggled only if an encoder value was actually read in.
STS_DI The bit displays the status of the digital input DI.
STS_DN Status direction down; for encoder value change from larger to smaller encoder positions (including zero
crossover)
STS_LOAD Feedback bit for CMP_VAL1 and CMP_VAL2. The 1SSI uses this bit to indicate that a comparison value is
loaded.
Technological Functions
Operating Instructions, 06/2010, A5E00124867-07
4.10 Control and Feedback Interfaces in Standard Mode
1SSI
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