Hohner FU 252 Operating Manual

Operating Manual

Signal converter for frequency -analog / serial

FU 252

Your partner for standard and special designs

- precise, reliable and fast -

Hohner Elektrotechnik GmbH
Gewerbehof 1
59368 Werne
Phone +49 - 2389 - 9878-0
Fax +49 - 2389 - 9878-27
E-Mail [email protected]
Web www.hohner-elektrotechnik.de

Operating Manual

FU 252

Signal converter for frequency - analog / serial

Product features:

 Input frequency range from 0.1 Hz to 1 MHz for full scale analog output
 Conversion time only 1 ms. (f > 2 kHz)
 Analog output with +/- 10 V or 0 resp. 4 to 20 mA
 Polarity of analog signal changes with change of the direction of rotation
 Suitable for conversion of quadrature signals (A/B) as well as single-channel

signals, with all HTL or TTL or RS422 formats and levels

 Suitable for conversion of the sum, the difference or the ratio of two frequencies
 RS232 or RS485 interface for serial readout of the input frequencies
 Programmable digital filters and programmable linearization curves
 Easy to set up by simple TEACH procedure, or by PC operator software

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Table of Contents

1. SAFETY INSTRUCTIONS AND RESPONSIBILITY .......................................................................4

1.1. General Safety Instructions ...................................................................................... 4

1.2. Use according to the intended purpose ................................................................... 4

1.3. Installation................................................................................................................ 5

1.4. Cleaning, Maintenance and Service Notes ............................................................. 5

2. COMPATIBILITY HINT ..............................................................................................................6

3. INTRODUCTION .......................................................................................................................7

3.1. Impulse input formats and input levels .................................................................... 7

3.2. Operating range ........................................................................................................ 8

3.3. Suitable encoders and sensors ................................................................................ 8

4. TERMINAL ASSIGNMENTS AND CONNECTIONS ....................................................................9

4.1. Example for use of TTL encoders ............................................................................. 9

4.2. Example for use of HTL encoders ........................................................................... 10

4.3. Proximity switches, photocells etc. ........................................................................ 10

4.4. Analog output ......................................................................................................... 10

4.5. Serial interface ....................................................................................................... 11

5. DIL SWITCH SETTINGS .......................................................................................................... 12

5.1. Basic mode of operation ........................................................................................ 12

5.2. Impulse levels and symmetric / asymmetric input formats ................................... 13

5.3. Analog output format ............................................................................................. 14

5.4. Selecting the RS232 or the RS485 serial interface ............................................... 15

5.5. Teach function, Test function, loading of default settings .................................... 15

6. COMMISSIONING ................................................................................................................. 16

6.1. Conversion of one only frequency (single or dual channel with direction signal) . 17

6.2. Conversion and combination of two independent frequencies ............................ 17

7. PC SETUP VIA OPERATOR SOFTWARE OS3.X ........................................................................ 18

8. PARAMETER DESCRIPTION ................................................................................................... 20

9. FREE PROGRAMMABLE LINEARIZATION ............................................................................... 27

10. MONITOR FUNCTIONS .......................................................................................................... 29

11. DATA READOUT VIA SERIAL INTERFACE ............................................................................... 31

12. DIMENSIONS ........................................................................................................................ 32

13. TECHNICAL SPECIFICATIONS ................................................................................................ 33

14. INTERNAL REGISTERS AND SERIAL CODES .......................................................................... 34

15. COMMISSIONING FORM ....................................................................................................... 36

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1. Safety Instructions and Responsibility

1.1. General Safety Instructions

This operation manual is a significant component of the unit and includes important rules and
hints about the installation, function and usage. Non-observance can result in damage and/or
impairment of the functions to the unit or the machine or even in injury to persons using the
equipment!

Please read the following instructions carefully before operating the device and observe all
safety and warning instructions! Keep the manual for later use.

A pertinent qualification of the respective staff is a fundamental requirement in order to use
these manual. The unit must be installed, connected and put into operation by a qualified
electrician.

Liability exclusion: The manufacturer is not liable for personal injury and/or damage to property
and for consequential damage, due to incorrect handling, installation and operation. Further
claims, due to errors in the operation manual as well as misinterpretations are excluded from
liability.

In addition the manufacturer reserve the right to modify the hardware, software or operation
manual at any time and without prior notice. Therefore, there might be minor differences
between the unit and the descriptions in operation manual.

The raiser respectively positioner is exclusively responsible for the safety of the system and
equipment where the unit will be integrated.

During installation or maintenance all general and also all country- and application-specific
safety rules and standards must be observed.

If the device is used in processes, where a failure or faulty operation could damage the system
or injure persons, appropriate precautions to avoid such consequences must be taken.

1.2. Use according to the intended purpose

The unit is intended exclusively for use in industrial machines, constructions and systems. Non­conforming usage does not correspond to the provisions and lies within the sole responsibility
of the user. The manufacturer is not liable for damages which has arisen through unsuitable
and improper use.

Please note that device may only be installed in proper form and used in a technically perfect
condition and in accordance to the Technical Specifications (see chapter 13). The device is not
suitable for operation in explosion-proof areas or areas which are excluded by the EN 61010-1
standard.

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1.3. Installation

The device is only allowed to be installed and operated within the permissible temperature
range. Please ensure an adequate ventilation and avoid all direct contact between the device
and hot or aggressive gases and liquids.

Before installation or maintenance, the unit must be disconnected from all voltage-sources.
Further it must be ensured that no danger can arise by touching the disconnected voltage­sources.

Devices which are supplied by AC-voltages, must be connected exclusively by switches,
respectively circuit-breakers with the low voltage network. The switch or circuit-breaker must
be placed as near as possible to the device and further indicated as separator.

Incoming as well as outgoing wires and wires for extra low voltages (ELV) must be separated
from dangerous electrical cables (SELV circuits) by using a double resp. increased isolation.
All selected wires and isolations must be conform to the provided voltage- and temperature­ranges. Further all country- and application-specific standards, which are relevant for structure,
form and quality of the wires, must be ensured. Indications about the permissible wire cross­sections for wiring are described in the Technical Specifications (see chapter 13).

Before first start-up it must be ensured that all connections and wires are firmly seated and
secured in the screw terminals. All (inclusively unused) terminals must be fastened by turning
the relevant screws clockwise up to the stop.

Overvoltages at the connections must be limited to values in accordance to the overvoltage
category II.

For placement, wiring, environmental conditions as well as shielding and earthing/grounding of
the supply lines the general standards of industrial automation industry and the specific shielding
instructions of the manufacturer are valid.

1.4. Cleaning, Maintenance and Service Notes

To clean the front of the unit please use only a slightly damp (not wet!), soft cloth. For the rear
no cleaning is necessary. For an unscheduled, individual cleaning of the rear the maintenance
staff or assembler is self-responsible.

During normal operation no maintenance is necessary. In case of unexpected problems, failures
or malfunctions the device must be shipped for back to the manufacturer for checking,
adjustment and reparation (if necessary). Unauthorized opening and repairing can have
negative effects or failures to the protection-measures of the unit.

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2. Compatibility Hint

This product is a successor model of the thousandfold proven converter type FU251. The new
product is suitable for a 100% replacement of the previous model, however some differences
must be observed with DIL switch settings and parameter settings.

S

ome essential advantages of FU252 compared to FU251 are:

 Maximum frequency 1 MHz (instead of 500 kHz)

 Total conversion time in-out = 1 ms (this was no more assured with

FU251 after the modifications necessary for RoHS conformity)

 Capability to accept even single-ended TTL input signals

(i.e. TTL input A only without inverted TTL signal /A)

 The setting of the analog format (+/-10 V, 0 … 10 V or 0/4 … 20 mA)

can be done by a supplementary DIL switch (no more PC required)

 Enhanced auxiliary output 5 V / 250 mA for encoder supply

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3. Introduction

FU 252 is a small and low-cost, but highly performing converter for industrial applications,
where one frequency or two different frequencies need to be converted into an Analog signal or
a serial data format. The unit has been designed as a compact module with 12 screw terminals
and a 9-position SUB-D connector (female). The housing is suitable for standard DIN rail
mounting.

3.1. Impulse input formats and input levels

The input site provides channels A and B and also the inverted lines /A and /B. All inputs are
designed for use with either HTL level or TTL level, with either single-ended format or
differential format (RS422).

The unit can convert the following formats to Analog and serial:
a

. Quadrature signals with a 90 phase displacement. Polarity of the Analog output and sign

of the serial data depend on the direction given by the A/B phase.

b. Single channel impulses on channel A. Input B sets the polarity of the output (LOW =

negative, HIGH = positive). In case of open (unconnected) inputs, please note:

 Open NPN inputs are evaluated as HIGH state
 Open PNP inputs are evaluated as LOW state

Open RS422 inputs may cause problems, therefore please set unused inputs to HTL by
means of the appropriate DIL switch

c. Fully independent frequencies on both channels A and B. The output signal can represent

the sum, the difference, the product or the ratio of the two input frequencies.

A

B

A

B

A

B

A and B, quadrature 90°

A=impulse, B=static polarity select

A and B: independant frequencies

a. b.

c.

+

-

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3.2. Operating range

The full scale frequency (i.e. the input frequency where the Analog output reaches 10 V or
20 mA) can be set in a range from –1 MHz to +1 MHz. The operating range of the unit can be
assigned to any frequency window inside this frequency range.
A “zero output frequency” can be set to guarantee defined operation of the converter with low
input frequencies.

For applications with unstable input frequencies, the unit provides programmable digital filters
for smoothing of the output signal.

3.3. Suitable encoders and sensors

The FU252 converter can accept the following impulse sources:

 Quadrature encoders with HTL level output (10 – 30 V) and either PNP or NPN or Push-

Pull or NAMUR characteristics, using A and B outputs wit 90° displacement

 Single channel impulse sources like proximity switches or photocells, providing HTL

level at PNP or NPN or Namur characteristics

 TTL / RS422 quadrature encoders with output lines A, /A ,B and /B

 Symmetric single channel sources with TTL / RS422 output, providing differential

signals (e.g. A and /A)

 Asymmetric single channel sources wit TTL level (without inverted signals, e.g. A only)

In general, HTL encoders will be supplied from the same source as the converter itself.
For supply of TTL encoders, the unit provides an auxiliary output of 5.5 volts
(stabilized, max. 250 mA).

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4. Terminal Assignments and Connections

We recommend connecting the Minus wire of the power supply to earth potential.
Please observe that, under poor earthing and grounding conditions, multiple earth connections
of screens and GND terminals may cause severe problems. In such cases it may be better to
have only one central earthing point for the whole system.

GND terminals 4, 6 and 12 are connected internally.
Under nominal conditions the current consumption of the unit is approx. 70 mA (aux. output
unloaded, see section 13 “Technical Specifications”). Lower input voltage and load of the aux.
output will increase the consumption accordingly.

1 2 3 4 5 6

7 8 9 10 11 12

Voltage output +/-10V

TTL: input /B HTL: n.c.

TTL: input B HTL: input B

GND ( - ) for analogue signals

Supply +18...30 VDC
(typ. 70 mA)

Current output 0-20mA / 4-20mA

TTL: input /A HTL: n.c.

TTL: input A HTL: input A

Control

Aux. output 5.5V

(max. 250 mA)

GND ( - )

GND ( - )

FU 252

4.1. Example for use of TTL encoders

If applicable, the encoder can be supplied from the FU252 converter. Where the encoder is
already supplied from a remote source, we recommend fully differential operation, with no
GND connection between encoder and converter (see figures a. and b.)

8
9

2
3

11 (+5.5V)

12 (GND)

+

-

TTL encoder

FU 252

Screen

A

A

B

B

A

A

B
B

8
9

2
3

11 (+5.5V)

12 (GND)

+

-

Screen

A

A

B

B

A

A

B
B

TTL encoder FU 252

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4.2. Example for use of HTL encoders

The encoder may be supplied from the same source as the converter, or from another source.

9

3

12 (GND)

GND

HTL encoder

FU 252

Screen

+24V

+
A

B

4.3. Proximity switches, photocells etc.

These connections are fully similar to a HTL incremental encoder. With single channel
operation, input B remains unconnected or can be used to select the output polarity. With use
of two independent frequencies for forming sum, difference or ratio, input B is used for the
second input frequency.

To use sensors with 2-wire NAMUR characteristics:

 set the inputs to HTL and NPN
 connect the positive wire of the sensor to the corresponding input and the negative wire

to GND.

4.4. Analog output

The unit provides a +/-10V voltage output and a 0 - 20mA / 4 – 20 mA current output at a
resolution of 14 bits, i.e. the voltage output operates in steps of 1.25 mV and the current output
operates in steps of 2.5 µA.

The nominal load of the voltage output is 2 mA and the current output accepts loads between
zero and 270 ohms.

The Analog ground uses a separate terminal, which however internally is connected to the GND
potential of the power supply.

GND

4

1

7

+/- 10V

20 mA

(R = 0 - 270 ohms)

(Imax = 2 mA)

Screen

Voltage out

Current out

 Important note: “Voltage out” and “Current out” cannot be used together.

Please do never connect mA and V simultaneously!

 The calibration depends on “Analog output format” (see chapter 5.3)

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4.5. Serial interface

The unit provides selectively a RS232 resp. RS485 interface, however only one of the two can
be used at a time. Serial communication allows to read out conversion results and to set
parameters and variables by PC, according to need.

5

4

3

2

1

9

8

7

6

GND int.

TxD

RxD

RS232

+5V

T+

T-

R+

R-

RS485

Sub-D-9 (female on unit site)

5

4

3

2

1

9

8 7

6

5

4

3

2

1

9

8 7

6

5

4 3

2

1

9

8 7

6

5

4 3

2

1

9

8 7

6

GND

TxD

RxD

PC

FU 252

Please connect only pins 2, 3 and 5 !

5

4

3

2

1

9

8 7

6

5

4

3

2

1

9

8 7

6

T+

T-

120 Ohms 120 Ohms

RS485- Bus

( 4- wire )

FU 252

120 Ohms 120 Ohms

R+

R-

T+

T-

R+
R-

5

4 3

2

1

9

8 7

6

5

4 3

2

1

9

8 7

6

T+

T-

120 Ohms

120 Ohms

( 2- wire )

FU 252

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5. DIL Switch Settings

There is one 8-position switch located on the top side (DIL1), and another 8-position switch is
located on the bottom side of the unit (DIL2). These switches provide major settings of the
desired properties of the unit.

 Changes of switch settings will become active only after cycling the

power supply of the unit!

 Positions 7 and 8 of switch DIL2 are for internal factory use only and

must both be set to OFF at any time during normal operation

5.1. Basic mode of operation

Positions 2, 3 and 4 of switch DIL1 on the top side allow setting the following operation modes:

1 2 3 4 5 6 7 8

on on on
on on off
on off on
on off off
off on on
off on off
off off on
off off off

Mode of operation

Channel A only
Ratio A : B
Sum A + B
Quadrature A / B / 90°
Channel B only
Product A x B
Difference A - B
A = impulse, B = direction / sign

DIL1

Setting example:
Quadrature input A / B / 90°

Top side

Sw i tc h DI L 1

Teach button

Bottom side

Swit ch DIL 2

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5.2. Impulse levels and symmetric / asymmetric input formats

Positions 5 and 7 of DIL1 together with positions 3 to 6 of DIL2 allow setting of all imaginable
combinations of levels and formats.

 All subsequent tables use the following definitions:

„0“ = switch OFF, „1“ = switch ON and
„x“ = position not important

 Switch settings refer to impulse inputs A / B only, but the

Control Input (terminal 10) provides always HTL / PNP format, i.e. you must
apply a positive voltage 10 – 30 volts to activate the function

 Where you use 2-wire sensors with NAMUR characteristics, connect the

positive pole of the sensor to the corresponding input terminal, and the
n

egative pole to GND

 Where subsequently you read (A) or (B), this indicates that the inputs expect

asymmetric signals and you will not need the corresponding inverted signals

 Where however you read (A and /A) or (B and /B), this indicates that the inputs

expect symmetric differential signals according to RS422 standard, i.e. it is
mandatory to apply also the inverted signals

5.2.1. Standard settings
If you just use encoders or sensors according to common industrial standards, and if also all

input signals should have the same level, you just can use one of the following three standard
settings and do not need to consider all further alternatives of switch settings.

DIL1 DIL2

Input Characteristics

Encoder Type

5 6 7 3 4 5 6

0

0

0 0 0

0

Asymmetric HTL input (A, B),

10 - 30 V level, NPN (switching to -) or

Push-Pull or NAMUR characteristics

Standard HTL encoders,

Proximity switches,

Photo switches etc.

1

0

0 0 0

0

Asymmetric HTL input (A, B),

10 - 30 V level, PNP (switching to +) or

Push-Pull characteristics

PNP Proximity switches,

Photo switches etc.

0

1

0 0 0

0

Symmetric TTL signals or

RS422 signals (A, /A), (B, /B)

(differential, including inverted signal)

Standard TTL encoders

providing A, /A, B, /B

output channels

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5

.2.2. Settings for special applications

Where you find that the standard settings shown before are not suitable for your application,
please go through the following setting options and find out the input levels and characteristics
you need.

DIL1 DIL2

Characteristics of input A

Characteristics of input B

5 6 7 3 4 5 6

x

x

0 0 0 1

TTL level (A)

TTL level (B)

x

x

0 0 1 0

HTL level (A and /A)

HTL level (B and /B)

x

x

0 0 1 1

TTL level (A)

TTL level (B and /B)

x

x

0 1 0 0

TTL level (A and /A)

TTL level (B)

x

x

0 1 0 1

HTL level NPN (A)

HTL level PNP (B)

x

x

0 1 1 0

HTL level NPN (A)

TTL level (B and /B)

x

x

0 1 1 1

HTL level NPN (A)

TTL level (B)

x

x

1 0 0 0

HTL level PNP (A)

TTL level (B and /B)

x

x

1 0 0 1

HTL level PNP (A)

TTL level (B)

x

x

1 0 1 0

HTL level PNP (A)

HTL level NPN (B)

x

x

1 0 1 1

TTL level (A and /A)

HTL level NPN (B)

x

x

1 1 0 0

TTL level (A)

HTL level NPN (B)

x

x

1 1 0 1

TTL level (A and /A)

HTL level PNP (B)

x

x

1 1 1 0

TTL level (A)

HTL level PNP (B)

5.3. Analog output format

The desired output format of the Analog output can be set by positions 1 and 2 of switch DIL2.

DIL2

Output format

1 2

0

0

Voltage 0 … +10 V

With this setting the format depends on the parameter „Analog
Mode“ which can be set by PC. Since the factory default setting

of parameter “Analog Mode” is “1”, the format will be a 0 …
+10 V output under default conditions.

0

1

Voltage +/- 10 V

1

0

Current 4 – 20 mA

1

1

Current 0 – 20 mA

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5.4. Selecting the RS232 or the RS485 serial interface

Position 1 of switch DIL1 selects between the RS232 interface and the RS485 interface. All
connection details have already been explained in section 4.5.

DIL1 / 1

Serial Interface

0

RS232 interface is active (RS485 is switched off)

1

RS485 interface is active (RS232 is switched off)

5.5. Teach function, Test function, loading of default settings

Positions 6 and 8 of switch DIL1 allow to set the following functions:

DIL1

Function

6 8

x

0

Unit returns to the factory default parameters after power-down

x

1

Unit always keeps the parameters according to customer setting

0

x

Push button and yellow LED operate in TEACH mode (see chapter 7)

1

x

Push button and yellow LED operate in TEST mode, Teach is disabled (see chapter 7)

After successful commissioning, please make sure to set positions
6 and 8 to “ON”. Otherwise, cycling of the power supply or touching the push button
inadvertently would result in overwriting your parameter settings.

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6. Commissioning

With all basic applications, you can use the Teach feature for commissioning of the unit.
Extended functions need a PC for setup and are described under section 7.

As a first step it is advisable to check the input frequencies by means of the LED marked
“Status”. DIL switch 6 must be set to ON for this test.

When you press the TEACH button one time, the yellow LED will be lit when the unit detects a
frequency on input A. The LED will be OFF when no input frequency can be detected.

When you press the TEACH button once more, you can also check input B (if applicable). With
all operation modes using two independent frequencies, again the yellow LED will be lit when
a frequency has been detected on input B.

With operation modes using input B to define the direction and polarity (quadrature or static),
the yellow LED will indicate that the actual input signals provide positive output (LED on) or
negative output (LED off). Where you like to get the other polarity, you must change the
information of direction on A/B inputs

 The TEACH function can only be used when the DIL switches are set for

operations with one input frequency only (i.e. A only, B only, quadrature A/B
or A = impulse and B = direction).

 You must switch over to combined operations A + B, A - B, A x B

or A : B only after you have successfully run the Teach function for both
channels. Parameter „Teach-Mode“ will determine if or if not an automatic
r

e-scaling will apply after switch-over.

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6.1. Conversion of one only frequency
(

single channel or dual channel with direction signal)

Make sure that the DIL switches are set according to the encoder you use, and that position 6
of switch DIL1 is OFF (Teach function active).

 Self-test: Upon power up, both front LED’s must be lit first, and the yellow status LED must

switch off after the self-test has been concluded successfully (approx.1 s).

 Scaling of the Analog output with use of the Teach function:

Press the Teach button one time. The status LED will blink in a slow sequence while the
unit waits for setting of the minimum frequency. Please make your encoder now generate
the frequency where you expect your Analog output to be zero (in general this will be 0 Hz
at standstill)

 Press the Teach button again. This stores your minimum frequency definition, the LED will

blink in a fast sequence and the unit waits for setting of the maximum frequency. Please
move your encoder now at a speed where you expect full scale Analog output.

 Press the teach button once more. This stores your maximum frequency definition and the

LED will switch off. After this Teach procedure, your Analog output is set to a 0 – 10 volts
range between the minimum and the maximum input frequency.

6.2. Conversion and combination of two independent

frequencies (A + B, A - B, A x B, A : B)

In principle, the Teach procedure is the same as described under 6.1. However, we must first
teach every of the two channels A and B separately.

 Set the DIL switch to “Channel A only” (see 5.1) and teach the minimum and the maximum

frequency for channel A like shown before.

 Now set the DIL switch to “Channel B only” and run the teach procedure for minimum and

maximum frequency of channel B.

 Finally, set the DIL switch according to the combination of the frequencies that you desire.

The unit is able to automatically re-scale the output swing in a way that you receive full
scale output when the result of the A/B calculation reaches the maximum
(see parameter “Teach Mode”).

Please observe that minimum and maximum frequency settings for

i

nputs A and B must never be “0” when you intend to use the ratio

f

unction A : B !

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7. PC Setup via Operator Software OS3.x

You can apply the full set of functions when you use a PC and our operator software OS3.x for
setup of the unit (at this time the actual version is OS3.2).
You can download this software and full instructions, free of charge, from our homepage

Connect your PC to the converter, using a serial RS232 cable like shown in section 4.5 of this
manual. Make sure, the cable only uses pins 2, 3 and 5. Pins 2 and 3 must be crossed.

Run the OS3.x software and you will see the following screen:

In case your text and color fields remain empty and the headline says „OFFLINE“, you must

verify your DIL switch setting and the serial settings of the unit. To access serial settings,
please select „COMMS“ from the menu bar.

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Ex-factory, all motrona units use the following serial default settings:

Unit No. 11, Baud rate 9600, 1 start/ 7 data/ parity even/ 1 stop bit

If the serial settings of your unit should be unknown, you can run the „SCAN“ Function

from the „TOOLS“ menu to find out.

On the left side of your screen you find the Edit window with all parameters.

Under „INPUTS“ you find some soft keys allowing to switch ON or OFF of the Control
commands. Indicator boxes in the RS column signal if the corresponding command is set by
serial communication. Indicator boxes in the PI/O column indicate if the same command is set
by hardware input.

Under OUTPUTS you can get information about the state of the unit. The indicator boxes
„Status A“ and „Status B“ especially serve to check the input frequencies:

 Status A will be lit while a frequency is detected on input A

(except with operating mode „B single“)

 Status B will be lit while a frequency is detected on input B

(except with operating modes „A single“, „A/B_dir“ and „A/B_90“)

The color bar in the “Output Value” field indicates the actual percentage of the output

signal in a range of +/- 100 %.

The Control keys allow Read-out, Transmission and saving of parameter settings.

 F

or enduring memorization of parameters entered by keypad, you should press

t

he ENTER key every time you have completed one line.

 Optionally you can also use the soft keys „Transmit“ or „Transmit All“ for

temporary storage of your last setting or all previous settings (storage until next
power-down), and finally use the „Store EEProm“ key when you like to have an
enduring storage of all settings transmitted before.

www.hohner-elektrotechnik.de 19

8. Parameter Description

Parameter

Description

Register Setting (.8):

Multiplier

Divisor

Offset

These operands allow converting the result to the desired engineering

units.
T

his conversion affects the numeric value for serial read out from

r

egister (:8) only, but not the scaling of the Analog output.
With settings Multiplier = 1,0000
Divisor = 1,0000
Offset = 00000
the readout from register < :8 > equals to the percental result
(xxx.xxx%) where 100,000% has been defined by the TEACH

minimum and TEACH maximum settings

Offset

Read-out from (:8)

=

Measuring result in % of full scale

x

Multiplier
Divisor

+

When you set “Divisor” to 0, this will completely skip all calculations.
T

his step is advisable when you need very fast response with the shortest

c

onversion time possible.

General Setting:

Direction

Filter A/B

Linearisation Mode

This parameter allows inversion of the polarity of the Analog output.
(Important only with operating modes A/B (2x90) or A = Impulse and B
= direction.
0

= no inversion

1

= output inverted

Digital filter for smoothing the Analog output with combined modes
(calculations from A and B)
0

0 = Filter off (immediate response to changes of the input signal)

0

1 = Filter with time constant 1,563 ms

0

2 = Filter with time constant 3,125 ms

0

3 = Filter with time constant 6,250 ms etc.

1

2 = Filter with time constant 3200 ms (slow response)

Please note:
These time constants are valid for sampling time settings of 1 ms. and higher
sampling times will correspondingly increase the time constant

0 = Linearisation OFF, parameters P1 to P16 are irrelevant.
1

= Linearisation in a range from 0% to 100 %

2

= Linearisation over full range –100% to +100%

See example under section 9 „Linearisation“

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Parameter

Description

Frequency Control

Input Filter

Frequency control and response characteristics to frequency gaps for

channels A and B. This setting is taken as a 4 bit binary value.
Range 00 – 15, default setting 10 (only to be changed in special case)*

Programmable hardware filter for the impulse inputs
0

= no filtering

1

– 3 : filter low – medium - high

Channel A Setting

Sampling Time A

Wait Time A

Filter A

Reset Value A

Time base for measuring the frequency on input A
R

ange 0 – 9,999 seconds

Setting 0 provides a sampling time of 750 µs

Zero setting time for missing frequency on input A.
R

ange 0.01 – 9.99 seconds
The Analog signal goes to zero when no input impulse appears during
the Wait Time.

Example:
With setting 0,01 s all frequencies <100 Hz will produce zero output

Digital filter for smoothing the Analog output with unstable frequencies
on input A.
0

0 = Filter off (immediate response to changes of the input signal)

0

1 = Filter with time constant 1.563 ms

0

2 = Filter with time constant 3.125 ms

0

3 = Filter with time constant 6.250 ms etc.

0

7 = Filter with time constant 100 ms (slow response)

Please note:
These time constants are valid for sampling time settings of 1 ms. and higher
sampling times will correspondingly increase the time constant

Range -1 100 000,0 to +1 100 000,0
Input A will be overwritten by this simulated frequency value, if the

control input is active and the “Reset A” function has been assigned to

the control input.

*) This Parameter is
only relevant when
remarkable Sampling
Times are used. It
determines the way
how the unit responds
to gaps within one
sampling period.

Sampling Time

Input A Input B: Bit0 = 1, Bit1 = 0. : Bit2 = 1, Bit 3 = 0

Input A Input B: Bit0 = 0, Bit1 = 1. : Bit2 = 0, Bit 3 = 1

www.hohner-elektrotechnik.de 21

Parameter

Description

Channel B Setting

Sampling Time B

Wait Time B

Filter B

Reset Value B

Time base for measuring the frequency on input B
R

ange 0 – 9,999 seconds
Setting 0 provides a sampling time of 750 µs

Zero setting time for missing frequency on input B.
R

ange 0.01 – 9.99 seconds
The Analog signal goes to zero when no input impulse appears during
the Wait Time.

Example:
With setting 0,01 s all frequencies <100 Hz will produce zero output

Digital filter for smoothing the Analog output with unstable frequencies
on input B.
0

0 = Filter off (immediate response to changes of the input signal)

0

1 = Filter with time constant 1.563 ms

0

2 = Filter with time constant 3.125 ms

0

3 = Filter with time constant 6.250 ms etc.

0

7 = Filter with time constant 100 ms (slow response)

Please note:
These time constants are valid for sampling time settings of 1 ms. and higher
sampling times will correspondingly increase the time constant

Range -1 100 000,0 to +1 100 000,0
Input B will be overwritten by this simulated frequency value, if the

control input is active and the “Reset B” function has been assigned to

the control input.

Analog Setting

Teach Minimum A

Teach Maximum A

Teach Minimum B

Teach Maximum B

These two couples of settings define your minimum and maximum input
frequency for input A and input B (if applicable), where your Analog
output moves between 0 V and 10 V.
This is how you can enter your minimum and maximum settings:
 either by operating the Teach pushbutton, like described already in

section 6.1

 or by entering the frequency settings directly by keyboard to the

parameter field of your screen, without using the TEACH function

www.hohner-elektrotechnik.de 22

Parameter

Description

Teach Mode

This parameter is only important when your application provides a

combination of the two inputs (e.g. A + B). The setting determines how to
scale the total result of the selected A/B calculation
T

each Mode = 0: The unit will automatically calculate a new “full scale”
output, resulting from the expected maximum values
that can come up with the combined result from A and B *

)

T

each Mode = 1: The total result will use the same scaling as applied to
input channel A *

)

T

each Mode = 2: Before calculating the combination result, the channel B
frequency will be pre-scaled using the conversion
parameters „Multiplier“ and „Divisor“ , so that a direct
compare between two frequencies of different scaling
can take place.

Analog Mode: Determines which Analog output format should be used (see 5.3):

V

Encoder

Min. Max.

Output Mode = 0

-10V ... 0 ... +10V

Encoder

Min.

Max.

V

Output Mode = 1
0 ... +10V

Min.

Max.

mA

Encoder

Output Mode = 2
4 ... 20 mA

mA

Encoder

Max.

Min.

Output Mode = 3
0 ... 20 mA

Analog Offset:

Parameter to shift the zero position of the Analog output over the full range

of +/- 9999 mV resp. +/-19,998 mA (if applicable). Normal setting is 0.

Analog Gain:

Allows setting the maximum swing of the Analog output.

Setting 1000 results in a full scale signal of 10 volts or 20 mA,
setting 500 will reduce the signal to 5 volts etc.

*)

Example: Provided you have set both inputs A and B to a range of 0 … 10 kHz for a 0 … 10 volts

output, and after this you switch over to the sum mode A + B:

Teach Mode = 0 would allow to apply the full frequency range of 10 kHz to each of the inputs at the
same time, because the automatic re-scaling function has set a full range scale of 20 kHz for the
expected maximum of the sum A + B.

Teach Mode = 1 would reach the full-scale output already with a sum of A + B = 10 kHz, because only

the 10 kHz / 10 volts scaling of input A will apply

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Parameter

Description

Serial

Communication:

Serial Unit No.:

Serial Baud Rate:

Serial Format:

Serial Protocol:

With RS 485 applications it is necessary to attach a specific address to
each unit, since up to 32 units can be connected to the same bus. You can
choose any address number between 11 and 99.

The address must however not contain a “0“ because these numbers are

reserved for collective addressing.

Setting

Baud Rate

0*

9600

1

4800

2

2400

3

1200

4

600

5

19200

6

38400

* = Factory setting

Setting

# data bits

Parity

# stop bits

0* 7 even

1

1 7 even

2

2 7 odd

1

3 7 odd

2

4 7 none

1

5 7 none

2

6 8 even

1

7 8 odd

1

8 8 none

1

9 8 none

2

* = Factory setting

Determines the sequence of characters sent, when you use the serial
output for cyclic data transmission under timer control
(xxxxxxx is the measuring value transmitted).

Setting “1

” will suppress transmission of the unit number, therefore the

transmission cycle is shorter than with setting “0

”

Unit No.

Serial Protocol = 0 :

1 1

+/- X X X X X X

LF

CR

Serial Protocol = 1 :

+/- X X X X X X

LF

CR

www.hohner-elektrotechnik.de 24

Parameter

Description

Serial Timer:

Serial Value:

This register determines the cycle time in seconds for cyclic

transmission when the Printer Mode is switched on.
Range 0.001 to 99.999 seconds.

With setting “0” all cyclic transmission is switched off and the unit will

only send data upon request (PC mode *)

Sets the code of the register of which the content should be sent with
cyclic transmission.
Setting range 00 – 09 (corresponds to register codes :

0 to :9)

and 10 - 19 (corresponds to register codes ;

0 to ;9)

For clarification of register codes see sections 10 and 11.

*) The serial port of the unit can operate in either “PC-Mode“ or in
“Printer Mode“.

With “PC-Mode“, the unit receives a request string and responds with a

corresponding data string. For details of the protocol see separate description

“SERPRO“.
With “Printer Mode“ the unit sends data without any request and under Timer

control as described subsequently.
As soon as the unit receives a character, it automatically switches over to PC
Mode and operates according to protocol. When for a period of 20 s no
character has been received, the unit switches automatically back to
“Printer Mode“ and starts cyclic data transmission again.

Input Setting:

Input Configuration:

Input Function:

Sets the switching characteristics of the „Control“ input (terminal 10):
0

= function „active HIGH“, 1 = function „active LOW“

Selects the function of the “Control” input (terminal 10):
0

= no control function

1

= Replaces the frequency applied to input A by a fixed frequency
value as set under parameter „Reset Value A“
2

= Replaces the frequency applied to input B by a fixed frequency
value as set under parameter „Reset Value B“
3

= Replaces the result of the combination A / B by a fixed value as
set under parameter „Reset Value A/B“
4

= Freezes the actual frequency value of input A
5

= Freezes the actual frequency value of input B
6

Freezes both frequencies A and B

7 = Starts a serial transmission of the defined register value

www.hohner-elektrotechnik.de 25

Parameter

Description

Both Channel Setting:

Multiplier:

Divisor:

Offset:

These settings provide a final scaling of the calculation result from
the combined operation modes A / B

Linearisation Setting:

P1_x to P16_x:

P1_y to P16_y:

Interpolation points for linearization (initial values)

Interpolation points for linearization (substitute values)

(For clarification see section 9)

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9. Free Programmable Linearization

This programmable feature allows the user to convert a linear input signal to a non- linear
Analog output. There are 16 programmable x/y coordinates available, which can be set in any
desired distance over the full conversion range. Between two coordinates, the unit uses linear
interpolation. Therefore it is advisable to use more coordinates in a range with strong curves
and only a few coordinates where the curvature is less.

To specify your desired linearization curve, you must first set the „Linearisation Mode“ register
to either 1 or 2.

Use registers P1(x) to P16(x) to specify the coordinates on the x-axis. These are the Analog
output values that the unit normally would generate according to the actual input frequency.
These settings must be in % of full scale.

Now enter the attached values to registers P1(y) to P16(y). These are the values that the Analog
output will generate instead of the x- values, i.e. P2(y) will substitute P2(x) etc.

 x-registers must use continuously increasing settings, i.e. P1(x) must

have the lowest and P16(x) must have the highest setting

 All entries use a percental format of xx.xxx% full scale.

Setting 000.000% means zero output and
setting 100.000% means full scale output.

 With Linearisation Mode set to 1, it is a must to set P1(x) to 0% and

P16(x) to 100%. Linearisation is defined in the positive range only and
the negative range will be a mirror image of the positive range with
reference to zero.

 With Linearisation Mode set to 2, it is a must to set P1(x) to –100%

and P16(x) to +100%. This enables the user to set curves which are
not symmetric to the zero position.

x

y

P1(x)= 0%
P1(y)=10%

Linearisation Mode = 1

x

y

Linearisation Mode = 2

P1(x)= -100%
P1(y)= 95%

P8(x)= 0%
P8(y)= 80%

P16(x)=+100%
P16(y)= -60%

*)

P16(x)=100%
P16(y)= 80%

*) Output mode = 0

www.hohner-elektrotechnik.de 27

You can visualize your curve on the PC screen or by means of an external oscilloscope.
For this, select TOOLS, then TEST and there „Analog Voltage Function“. The unit will now
simulate a repeating frequency course over the full range and generate the Analog signal
accordingly. When you use the Scope function of the operator software, you must set the serial
code to „:

1” to record the Analog output.

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10. Monitor Functions

The monitor function of the OS3.2 PC software allows to display some important data on the PC
screen with a continuous refresh cycle.

Select „Monitor“ from the „Tools“ menu to open the basic view of the monitor window. Click to
“Define” to open the definition window. You will find a list with all accessible parameters and

actual values, where however the texts may be unfounded.

With FU252, only the following register codes make sense:

C1

C2

Description

: 8 Actual conversion result in % of full-scale, format xxx.xxx % *)

: 9 Actual frequency on input A in Hz, resolution 0.1 Hz, format xxx xxx.x Hz

; 1 Actual frequency on input B in Hz, resolution 0.1 Hz, format xxx xxx.x Hz

; 3 Actual output voltage of the Analog output, scaling 0 … 10 000 millivolts

*) In accordance to the applied conversion scaling see chapter 8.

www.hohner-elektrotechnik.de 29

Click to the Status field, next to the desired register code (where you read ON or OFF). Now you
can toggle this position between ON and OFF by touching any key.

Set all of the register codes to ON which you afterwards would like to trace on the monitor.
Switch all unused register codes to OFF.

To change the text shown with the register code, click to the corresponding text field. The same

text will now appear in the “Text Editor” window below the parameter window. Rename the

text according to your desire and press ENTER to store the new text in the corresponding
monitor line.

When all desired codes have been set to ON and the texts have been renamed according to
need, click OK. Where, besides the display data on the screen, you also like to record all data to
a file on your hard disc, click first to „Store to File“ and set the corresponding check box.

After starting the monitor, you will see the following window where all values are updated
continuously:

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11. Data Readout via Serial Interface

All register codes from section 10 are also available for serial readout by PC or PLC. For
communication the FU252 converter uses the Drivecom Protocol according to ISO 1745. All
protocol details can be found in our manual S

ERPRO_2a.doc which is available for download

from our homepage

To request for a data transmission you must send the following request string to the converter:

EOT

AD1

AD2

C1

C2

ENQ

EOT = control character (Hex 04)

AD1 = unit address, High Byte
AD2 = unit address, Low Byte
C1 = register code, High Byte
C2 = register code, Low Byte

ENQ = control character (Hex 05)

The following example shows the request string for readout of the actual frequency of input A
(code :9) from a unit with unit address 11:

ASCII Code:

EOT 1 1 : 9

ENQ

Hex Code:

04

31

31

3A

39

05

Binary Code:

0000 0100

0011 0001

0011 0001

0011 1010

0011 1001

0000 0101

After a correct request, the unit will respond:

STX

C1

C2

x x x x x x x

ETX

BCC

STX = control character (Hex 02)

C1 = register code, High Byte
C2 = register code, Low Byte
xxxxx = readout data
ETX = control character (Hex 03)

BCC = block check character

For all further details see SERPRO_2a.doc.

www.hohner-elektrotechnik.de 31

12. Dimensions

74 mm (2.913’’)

91mm (3.583’’)

40 mm (1.575’’)

79 mm (3.110’’)

Front view

Side view

Top view

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13. Technical Specifications

Power supply:

Input voltage:

Protection circuit:
Ripple:

Consumption:

18 … 30 VDC

reverse polarity protection
≤ 10 % at 24 VDC

approx. 75 mA at 24 V (unloaded encoder supply)

Connections:

Connector type:

screw terminals, 1.5 mm² / AWG 16

Encoder supply:

Output voltage:
Output current:

+ 5.5 VDC / +/- 5 %
max. 250 mA

Incremental Input:

Signal levels:

HTL characteristic:
HTL internal resistance:
Channels:
Frequency:

Measurement accuracy:

RS422: Differential voltage > 1 V

TTL: LOW: 0 … 0.5 V / HIGH: 2.5 … 5.3 V
HTL: LOW: 0 … 3 V / HIGH: 10 … 30 V

NPN / PNP
Ri ≈ 4.75 kOhm
A, /A, B, /B
max. 1 MHz at RS422 and TTL symmetrical
max. 200 kHz at HTL and TTL asymmetrical

0.02 % +/- 1 digit

Control Input:

Application:

Signal levels:

Pulse time:

proximity switches or control commands

LOW < 3 V / HIGH >10 V

min. 5 ms

Analog outputs:

Voltage:

Current:
Resolution:
Accuracy:
Resolution per bit:
Reaction time
(standard operation):

Reset time (in case of

a sudden interruption):

- /+ 10 V (external load max. 5 kOhm)

0/4 … 20 mA (burden max. 270 Ohm)
14 Bit

0.1%

1.25 mV / 2,5 µA

depends on sampling time and frequency;
approx. 1 ms (fin > 2 kHz); 1/f in (fin < 1 kHz)

5 ms (without average), 700 ms (max. average)

Housing:

Material:

Mounting:
Dimensions (w x h x d):
Protection class:

Weight:

plastic

35 mm top hat rail (according to EN 60715)
40 x 79 x 91 mm / 1.5748 x 3.1102 x 3.5827 inch
IP20

approx. 190 g

Ambient
temperature:

Operation:
Storage:

0 °C … +45 °C / +32 … +113 °F (not condensing)

-25 °C … +70 °C / -13 … +158 °F (not condensing)

Failure rate:

MTBF in years:

75.2 a (long-term usage at 60 °C / 140 °F )

Conformity and
standards:

EMC 2004/108/EC:
Guideline 2011/65/EU:

EN 61000-6-2, EN 61000-6-3, EN 61000-6-4
RoHs-conform

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14. Internal Registers and Serial Codes

Commands:

#

Name

Code

CmdBit

SerStatus

BusStatus

ExtStatus

7

FreezeBoth

61

0040

Yes

No

Yes

8

FreezeB

62

0020

Yes

No

Yes

9

FreezeA

63

0010

Yes

No

Yes

10

ResetBoth

64

0008

Yes

No

Yes

11

ResetB

65

0004

Yes

No

Yes

12

ResetA

66

0002

Yes

No

Yes

13

ActivateData

67

1000

Yes

No

No

14

StoreEEProm

68

0001

Yes

No

No

Parameters:

#

Menu

Name

Code

Min

Max

Default

0

Register-Setting(:8)

Multiplier

00

-1000000

1000000

10000

1 Divisor

01 0 1000000

0

2 Offset

02

-1000000

1000000

0

3

General-Setting

Direction

46

0 1 0

4 FilterAB

11 0 12

0

5 LinearisationMode

08

0 2 0

6 FrequencyControl

D2 0 15

10

7 InputFilter

D3

0 3 0

8

Channel-A-Setting

SamplingTimeA

33 0 9999

0

9 WaitTimeA

09 1 999

100

10 FilterA

D6

0 7 0

11 ResetValueA

D7

-10000000

10000000

0

12

Channel-B-Setting

SamplingTimeB

34 0 9999

0

13 WaitTimeB

10 1 999

100

14 FilterB

D8

0 7 0

15 ResetValueB

D9

-10000000

10000000

0

16

Analog-Setting

TeachMinA

03

-10000000

10000000

0

17 TeachMaxA

04

-10000000

10000000

10000

18 TeachMinB

05

-10000000

10000000

0

19 TeachMaxB

06

-10000000

10000000

10000

20 TeachMode

12

0 2 0

21 AnalogMode

07

0 3 1

22 AnalogOffset

47

-9999

9999

0

23 AnalogGain

48 0 10000

1000

24 Reserved

E0 0 9999

1000

25

Serial-Communication

SerialUnitNo.

90 0 99

11

26 SerialBaudRate

91

0 6 0

27 SerialFormat

92

0 9 0

28 SerialProtocol

30

0 1 0

29 SerialTimer

31 0 99999

0

30 SerialValue

32 0 19

0

www.hohner-elektrotechnik.de 34

#

Menu

Name

Code

Min

Max

Default

31

Input-Setting

InputConfiguration

E2

0 1 0

32 InputFunction

E3

0 7 0

33

Both-Channel-Setting

Multiplier

13

-1000000

1000000

10000

34 Divisor

14 1 1000000

10000

35 Offset

15

-1000000

1000000

0

36

Linearisation-Setting

P1(x)

A0

-100000

100000

100000

37 P1(y)

A1

-100000

100000

100000

38 P2(x)

A2

-100000

100000

100000

39 P2(y)

A3

-100000

100000

100000

40 P3(x)

A4

-100000

100000

100000

41 P3(y)

A5

-100000

100000

100000

42 P4(x)

A6

-100000

100000

100000

43 P4(y)

A7

-100000

100000

100000

44 P5(x)

A8

-100000

100000

100000

45 P5(y)

A9

-100000

100000

100000

46 P6(x)

B0

-100000

100000

100000

47 P6(y)

B1

-100000

100000

100000

48 P7(x)

B2

-100000

100000

100000

49 P7(y)

B3

-100000

100000

100000

50 P8(x)

B4

-100000

100000

100000

51 P8(y)

B5

-100000

100000

100000

52 P9(x)

B6

-100000

100000

100000

53 P9(y)

B7

-100000

100000

100000

54 P10(x)

B8

-100000

100000

100000

55 P10(y)

B9

-100000

100000

100000

56 P11(x)

C0

-100000

100000

100000

57 P11(y)

C1

-100000

100000

100000

58 P12(x)

C2

-100000

100000

100000

59 P12(y)

C3

-100000

100000

100000

60 P13(x)

C4

-100000

100000

100000

61 P13(y)

C5

-100000

100000

100000

62 P14(x)

C6

-100000

100000

100000

63 P14(y)

C7

-100000

100000

100000

64 P15(x)

C8

-100000

100000

100000

65 P15(y)

C9

-100000

100000

100000

66 P16(x)

D0

-100000

100000

100000

67 P16(y)

D1

-100000

100000

100000

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15. Commissioning Form

Date:

Unit:

FU252

Operator:

Software:

Serial No.:

General Setting

Direction:

Filter A/B:

Linearisation Mode:

Frequency Control:

Input Filter:

Input

Channel A

Channel B

Sampling Time::

-

Wait Time:

-

Filter

-

Reset Value:

-

Analog Setting

Channel A

Channel B

Teach Minimum:

Teach Maximum

Teach Mode

Analog Offset

Analog Mode

Analog Gain

Serial Communication

Serial Unit No

Serial Protocol

Serial Baud Rate

Serial Timer

Serial Format

Serial Value

Input Setting:

Input Configuration

Input Function

0

Both Channel Setting:

Multiplier:

Divisor:

Offset:

Linearization

P01_X:

P01_Y:

P09_X:

P09_Y:

P02_X:

P02_Y:

P10_X:

P10_Y:

P03_X:

P03_Y:

P11_X:

P11_Y:

P04_X:

P04_Y:

P12_X:

P12_Y:

P05_X:

P05_Y:

P13_X:

P13_Y:

P06_X:

P06_Y:

P14_X:

P14_Y:

P07_X:

P07_Y:

P15_X:

P15_Y:

P08_X:

P08_Y:

P16_X:

P16_Y:

DIL Switch 1

DIL Switch 2

-1-

-2-

-3-

-4-

-5-

-6-

-7-

-8- -1-

-2-

-3-

-4-

-5-

-6-

-7-

-8-

OFF

OFF

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