Siemens Simatic S7-200 System Manual page 329

Speed_SP (speed setpoint) is drive speed as a percentage of full speed. Negative values of Speed_SP
cause the drive to reverse its direction of rotation. Range: –200.0% to 200.0%
Error is an error byte that contains the result of the latest communications request to the drive. Table 11-6
defines the error conditions that could result from executing the instruction.
Status is the raw value of the status word returned by the drive. Figure 11-3 shows the status bits for
Standard Status Word and Main Feedback.
Speed is drive speed as a percentage of full speed. Range: –200.0% to 200.0%
Run_EN (RUN enable) indicates whether the drive is running (1) or stopped (0).
D_Dir indicates the drive's direction of rotation.
Inhibit indicates the state of the inhibit bit on the drive (0 – not inhibited, 1 – inhibited). To clear the inhibit
bit, the Fault bit must be off, and the RUN, OFF2, and OFF3 inputs must also be off.
Fault indicates the state of the fault bit (0 – no fault, 1 – fault). The drive displays the fault code. (Refer to
the manual for your drive). To clear the Fault bit, correct the cause of the fault and turn on the F_ACK bit.
High byte
15 14 13 12
1 = Converter output is counter-clockwise
Reserved for future use: These bits might not always be zero
Figure 11-3 Status Bits for Standard Status Word for MicroMaster 3 and Main Feedback
Using the USS Protocol Library to Control a MicroMaster Drive
11 10 9 8 7 6 5
0 = OFF3 (Quick stop command present)
1 = Switch-on inhibit
1 = Drive warning present
1 = Not used (always 1)
1 = Serial operation allowed
0 = Serial operation blocked – local operation only
1 = Frequency reached
0 = Frequency not reached
1 = Converter output is clockwise
Low byte
4 3 2 1 0
1 = Ready to start
1 = Ready to operate
1 = Operation enabled
1 = Drive fault present
0 = OFF2 (Coast stop command present)
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