VibroSystM DMV-100, Руководство по установке

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42 DMV-100 Rotor Creep and Speed Detector - Installation Manual
5.4.2.2 Prescale value
The speed indicator calculates the machine rotational speed (RPM) according to the following formula:
where: freq. (Hz) = poles per second (calculated on pulse signal input from DCC-631)
60 = constant value

= 1 / number of poles on the monitored machine.
•
The freq. (Hz) represents the number of pulses (1/pole) per second received from the DCC-631 conditioner
•
The total number of pulses received per minute (freq. (Hz) x 60) has to be divided by the number of poles
to obtain a speed in RPM. The

factor, called prescale value , is a fraction resulting from the division of 1
by the number of poles.
Example: An 80-pole rotor corresponds to a prescale value of 1,25 x 10
-2
(

= 1 / 80)
Note that during programming, the display uses scientific notation.
In this example, the following parameters will be set to the following values:
•
Prescaling value X (mantissa): 1,25 (example value)
•
Prescaling value Y (exponent): 10
-2
(example value)
•
Decimal point position: 0000.0 (example setting)
•
Average type: set to simple average (suggested value)
•
Average times: set to 16 for a 320 ms refresh period (suggested value)
•
Auto-zero time A: set to 1.0 (example value)
•
Power interruption memory: set to OFF (example value)
•
Display refresh period: set to 0.5 (example value)
•
Display value selection: set to PV (suggested value)
•
Automatic Display return: set to 10 seconds (suggested value)
•
Position meter type: set to incremental (suggested value)
•
Position upper limit: set to 135 (example value)
•
Position meter lower limit: set to 0 (example value)
•
Linear current model: set to 4-20mA (required value)
•
Linear output upper limit: set to 135 (example value)
•
Linear output lower limit: set to 0 (example value)
Speed = freq. (Hz) x 60 x
