Siemens SIMATIC FM 453, Manual

Page: 282 / 380

9-82
FM 453 Servo Drive / Step Drive Positioning Module
C79000-G7076-C453-01
Rotation monitoring
The following prerequisites must be met for the “Rotation monitoring” func-
tion:
1. External zero pulse (NIX) which is generated cyclically, precisely once
per motor revolution
Condition:
At the maximum speed of the stepper motor, a signal length of
∆
t
w
2
@
FM cycle must be assured for the external zero pulse!
2. Connection to the “Controller message” (NL) input of the FM 453’s front
panel connector.
3. Parameterization of the type of reference point approach in modes
0 ... 3 (MD18)
4. Parameterization of the external zero pulse (MD37.26)
5. Use of the current-sourcing pattern zero signal is not allowed!
Activation of rotation monitoring:
For “rotation monitoring” single function, see Section 9.3.2
Error message:
S
Error “Digital input not parameterized” (see Trouble-shooting, Table
11-7, Kl. 3/Nr. 30)
Selecting function without parameterization for NIX
S
“Rotation monitoring” error (see Troubleshooting, Table 11-7,
Cl. 3/No. 66)
– Motor turns too slowly (during acceleration/travel)
– Motor turns too fast (during acceleration/travel)
– External zero pulse failed
– Incorrect number of increments per motor revolution parameterized
(MD52)
Function description:
The external zero pulse is used as described below to monitor the motor rota-
tion as specified in controlled operation (see Figure 9-12)
S
The first NIX received synchronizes rotation monitoring.
S
With every further NIX received, the system verifies whether the current
pulse output of the stepper motor is within a window n
360
° "
45
°
. The
error “Rotation monitoring” is triggered by the occurrence of NIX edges
which are outside the allowed window.
S
With every FM cycle (2 ms) the system verifies whether the pulse output
is outside a window
"
(360
°
+ 45
°
) since receipt of the last NIX. Posi-
tioning outside this allowable window also triggers the “Rotation moni-
toring” error.
Description of Functions