Siemens SIMATIC S5 ET 200U - Diagnostics Byte

9-27
ET 200U Distributed I/O Station
EWA 4NEB 812 6087–02b
 Diagnostics Byte (Byte 1)
The diagnostics byte is byte 1 of the first input word. Byte 0 has no sig-
nificance.
The diagnostics byte provides information on the following items (see
also Figure 9-15).
– Preset position resolution
– Preset mode
– The reaching of setpoints
– Signal status of the sync bit for position decoding
Bit No.:
X R P/C OV S
2
S
1
S
y
R
76 432105
Position Resolution
Single
Double
Quadruple
Not Possible
Position Decoding
Counter
No Counter Overflow
Counter Overflow
Setpoint 2 Reached
Setpoint 2 Not Reached
Setpoint 1 Reached
Setpoint 1 Not Reached
Sync Bit Set
Sync Bit Not Set *
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
* If the sync bit is not set, a reference point approach must
be implemented before operation can continue in the PO-
SITION DECODING mode.
X = irrelevant
Mode
Figure 9-15 Diagnostics Byte
Function Modules