Malfunctions - Hengstler signo 721 Benutzerhandbuch

Note
Preset 2 is the main preset value which is used to control the automa-
tic reset routine in the counter. Output signal P1 is always bistable
and is deleted by signal P2.
Correction (COR)
In the menu item "correction" the current count can be corrected via
keypad or set to any desired value (as far as feasible).
Note
Output signals cannot be set via keypad!
Prescaler (PSC)
The prescaler is a variable multiplication factor by which the pulses
fed to the counter can be converted to a meaningful unit and dis-
played in this form. It can be set in a range from 0.001 ... 9.999.
Example:
A flow meter produces 173 pulses per 100 litres. Instead of the num-
ber of pulses, the display shall indicate the actual flow in litres.
In general the following applies for the conversion of pulse sequences
to meaningful units:
Number of pulses x prescaler value = desired indication
or
Prescaler value (PSC) =
For above example: PSC =
Further typical applications required a prescaler:
• Compensation for worn measuring wheels
• Conversion of measuring units, i.e. metric system to inches
• Registration of processes using multiple tools, e.g. simultaneous
punching of 6 parts.
Operation mode of the prescaler
Each pulse registered at the count input is multiplied by the set
weighting factor. Only integer values are displayed - the remainder is
added to the following pulse.
Note
Remainder values are deleted when the supply
voltage is switched off, also after reset and auto reset.
Examples:
A weighting factor of 1.300 is programmed, i.e. each pulse will be
multiplied by 1.300. The display indicates integer values; therefore the
display will show the following sequence of numbers:
N. B.
registered
At a prescaler value
pulses
> 1 the product of
1
counting frequency
2
x prescaler may not
3
exceed a value of ≤
4
5000.
5
6
7
–
–
Sach-Nr. 2 721 091; Version 1250100MW
desired indication
number of pulses
100
= 0.578
173
calculated display
result value
1,300 1
2,600 2
3,900 3
5,200 5
6,500 6
7,800 7
9,100 9
– –
– –
The result for a
registered
weighting factor
pulses
< 1 is:
1
2
3
4
5
6
7
–
–

8. Malfunctions

Errors and malfunctions may occur during initial and further operati-
on of the counter. The reasons for such errors and malfunctions are
most likely to be found in incorrect programming, switch setting or in
the external connections. Therefore, please read the following check
list carefully if any malfunctions occur and correct the errors as far as
possible.
General causes of malfunctions
• Is the supply voltage identical to the voltage stated on the
counter?
• Is the supply voltage fed to the proper terminals - and, for DC
supplies, with the proper polarity?
• Is the max. counting frequency exceeded?
• Are the amplitude levels for voltage pulse generation correct?
• Does the programming correspond to the specific application?
No indication on the display
• Is the supply voltage switched on?
• Is the supply voltage connected properly?
Prescaler cannot be programmed
• Keypad locked (switches 6 and 7/keylock input)?
Counter shows wrong count or does not count at all
• Count input connected properly?
• Correct programming?
• Contact bounce, interference pulses, pulse generator oscillations?
• Reset or application input triggered?
• Ground connection counter - pulse generator ok?
• Does the contact maker or pulse generator work properly?
• Is the max. counting frequency exceeded?
• Pulse width or interval too short?
• Count input bridged?
• Prescaler set to zero or a very small value?
Please contact your local distributor if you cannot determine the cau-
se of the error or malfunction.
Please attach a short description of the operating conditions (malfun-
ction, programming, connection) when sending the unit back. This en-
ables us to search specifically for a possible error and ensures that
your counter will be returned as soon as possible.
calculated display
result value
0,400 0
0,800 0
1,200 1
1,600 1
2,000 2
2,400 2
2,800 2
– –
– –
21/24