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10 weighing function (fb_weigh), Weighing function (fb_weigh) – NORD Drivesystems BU0550 User Manual

Page 77

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3 AWL (Instruction List, IL)

BU 0550 GB-0813

77

3.5.10

Weighing function (FB_Weigh)

This module is used to determine the average torque during travel with a constant speed. From this value,
physical values e.g. the moved weight can be determined.

The FB is started via a positive flank on theEXECUTE input. With the flank, all inputs are adopted by the FB.
The FI moves with the speed which is set under SPEED. After the elapse of the time which is set under
STARTTIME the measurement is started. The duration of the measurement is defined under
MEASURETIME. The FI stops after the elapse of the measurement time. If the input REVERSE = 1, the
measurement restarts, however with a negated speed. Otherwise the measurement is complete; the output
DONE changes to 1 and the measurement result is in VALUE.

As long as the measurement process is running, BUSY is active.

The scaling of the measurement result VALUE is 1 = 0.01% of the rated torque of the motor.

Call-up of another Motion FB stops the measurement function and the output ABORT changes to 1.

All outputs of the FB are reset with a new positive flank on EXECUTE (Reset).

Table 103 FB_Weigh

NOTE

Only one instance of this FB is permissible in the PLC program!

VAR_INPUT

VAR_OUTPUT

Input

Explanation

Type

Output

Explanation

Type

EXECUTE

Execute

BOOL

DONE

Measurement ended

BOOL

REVERSE

Change of rotation direction

BOOL

BUSY

Measurement running

BOOL

STARTTIME

Time until start of measure-
ment in ms

(<2000ms)

INT

ABORT

Measurement aborted

BOOL

MEASURETIME

Measurement time in ms

(60 to 2000ms)

INT

ERROR

the FB has an error

BOOL

SPEED

Measurement speed in %
(16#4000 corresponds to
100%)

INT

ERRORID

Error code

INT

VALUE

Measurement result

INT

ERRORID

Explanation

0

No error

0x1000

FI not switched on

0x1101

Setpoint frequency not parameterised as a setpoint (P553)

0x1C00

STARTTIME value range exceeded

0x1C01

MEASURETIME value range exceeded

0x1602

The tolerance of the measurement values with respect to each other is greater than 1/8