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
7
6
4
3
2
1
0
5
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