Ahlborn ALMEMO 202-S User manual

____________________________
Operating instructions
English
V7 special measuring instrument
ALMEMO®202-S and ALMEMO®204
for digital sensors
V1.0
11.05.2023
www.ahlborn.com

2
1. OPERATING CONTROLS
(1) Measuring sockets M0, M3
(depending on type)
M0...M3 for digital ALMEMO®sen-
sors DIGI, D6, D7 only
M0.0...M3.9 for up to 40 meas.
chan.
(2) Output socket A1, A2
A1 USB interface (ZA 1919-DKU)
Optic fiber (ZA1909-DKL)
V24 (ZA1909-DK5)
Ethernet (ZA1945-DK)
Trigger input (ZA1006-ET/EK2)
Relay outputs (ZA1006-EGK)
Analog output 1 (ZA160x-RI/RU)
A2 Network cable (ZA1999-NK5/NKL)
Plug-in memory (ZA1904-SD)
Trigger input (ZA1006-ET/EK2)
Relay outputs (ZA1006-EKG)
Relay trigger adapter (ZA1006-RTA)
Analog output 2 (ZA160x-RI/RU)
(3) Connection socket DC 12V
Mains adapter(ZA1312-NAx,12V,min.1A)
Cable, el. isol. (ZA2690-UK, 10-30V)
(4) LCD graphics display
7 rows for functions
1 row for softkeys F1,◄,▲,►, F2
Shown in brackets: < MENU >, <FCT>
(5) Operating keys
ON To switch device ON
To switch device OFF: press and hold down
F1 , F2 Function keys (Softkeys)
▲, ▼... M: To select a measuring point
▲, ▼, ►F: To select a menu
PROG , ▼... F: To select a function
◄... return to menu selection
<M ◄◄ >go directly to the meas. menu
<F ►► >go directly to the meas. menu
PROG To program
▲, ▼, ►... To enter data
Rear of device:
(6) Battery compartment
3 AA alkaline-manganese batteries

3
2. TABLE OF CONTENTS
1. Operating controls ...................................................................................... 2
2. Table of Contents........................................................................................ 3
3. General ....................................................................................................... 7
3.1 Warranty............................................................................................. 7
3.2 Standard delivery ............................................................................... 8
3.3 Waste disposal................................................................................... 8
4. Safety instructions ...................................................................................... 9
4.1 Special notes on use........................................................................ 10
4.2 Handling batteries / rechargeable batteries correctly ...................... 10
5. Introduction............................................................................................... 11
5.1 Functions of the ALMEMO®202-S and ALMEMO®204 .................. 12
5.1.1 Sensor programming ................................................................... 12
5.1.2 Measuring operation .................................................................... 13
5.1.3 Process control ............................................................................ 14
6. Putting into service ................................................................................... 17
7. Power supply ............................................................................................ 18
7.1 Battery operation and supply voltage monitoring ........................... 18
7.2 Mains operation ............................................................................... 18
7.3 External DC voltage supply ............................................................. 18
7.4 Sensor supply .................................................................................. 19
7.5 Switching ON / OFF, reinitialization ................................................. 19
7.6 Data buffering .................................................................................. 19
8. Connecting sensors / transducers............................................................ 20
8.1 Standard sensor (V5)....................................................................... 20
8.2 D6 sensors....................................................................................... 20
8.3 D7 sensors....................................................................................... 20
8.4 Measuring inputs und additional channels....................................... 21
8.5 Potential separation ......................................................................... 21
9. Display and keypad .................................................................................. 22
9.1 Display and menu selection............................................................. 22
9.2 Measured value display and status symbols ................................... 22

2. Table of Contents
4
9.3 Function keys................................................................................... 23
9.4 Function selection ............................................................................ 24
9.5 To enter data .................................................................................... 24
10. Menu selection..................................................................................... 26
11. Measuring menus ................................................................................ 27
11.1 Sensor display menu ....................................................................... 27
11.1.1 Measuring channel selection ................................................... 27
11.2 Measured value correction and compensation................................ 27
11.2.1 Setting measured values to zero ............................................. 28
11.2.2 Atmospheric pressure compensation ...................................... 28
11.3 Measuring points list menu .............................................................. 29
11.4 User menu U2 - data logger ............................................................ 29
12. Measured data scanning and output ................................................... 30
13. Usermenus........................................................................................... 31
13.1 Functions ......................................................................................... 31
13.2 Configuration of user menus............................................................ 32
14. Functions menus.................................................................................. 34
14.1 Maximum, minimum, individual value memory................................ 34
14.2 Averaging......................................................................................... 35
14.2.1 Smoothing meas. values by means of a sliding average ........ 35
14.2.2 Averaging over manually selected meas. operations .................. 36
14.2.3 Averaging over time ................................................................. 37
14.2.4 Averaging over a cycle............................................................. 37
14.2.5 Averaging over measuring points ............................................ 38
14.2.6 Volume flow measurement ...................................................... 38
14.3 Two-point adjustment with Setpoint entry........................................ 39
14.4 Scaling ............................................................................................. 39
14.5 Data logger functions....................................................................... 40
14.5.1 Internal data memory............................................................... 40
14.5.2 External plug-in memory incorporating Memory card.............. 40
14.5.3 Numbering of measuring operations........................................ 41

2. Table of Contents
5
14.5.4 Once-only saving of all measuring points................................ 41
14.5.5 Cyclic saving of all measuring points....................................... 42
14.5.6 Memory capacity, memory output and clearing ....................... 42
14.5.7 Scanning configuration ............................................................ 43
14.5.8 Scan mode............................................................................... 43
14.5.9 Starting and stopping measuring operations ........................... 45
15. Sensor programming ........................................................................... 47
15.1 Selecting the input channel.............................................................. 47
15.2 Channel designation ........................................................................ 47
15.3 Averaging mode............................................................................... 48
15.4 Locking the sensor programming .................................................... 48
15.5 Limit values ...................................................................................... 48
15.6 Correction values ............................................................................. 49
15.7 Scaling, decimal point setting .......................................................... 49
15.8 Changing the units ........................................................................... 50
15.9 Selecting the measuring range ........................................................ 50
15.10 Sensor configuration.................................................................... 52
15.11 Multi-point calibration................................................................... 52
15.12 Special functions.......................................................................... 52
15.12.1 Cycle factor .............................................................................. 53
15.12.2 Actions triggered by limit value infringement ........................... 53
15.12.3 Analog output start / end.......................................................... 54
15.12.4 Minimum sensor supply voltage .............................................. 54
15.12.5 Output function......................................................................... 55
15.12.6 Reference channels ................................................................. 55
15.12.7 Element flags ........................................................................... 56
16. Device configuration ............................................................................ 57
16.1 Date and time-of-day ....................................................................... 57
16.2 Device designation........................................................................... 57
16.3 Language ......................................................................................... 57
16.4 Illumination and Contrast ................................................................. 57

2. Table of Contents
6
16.5 Interface, device address and networking ....................................... 58
16.6 Baud rate, data format ..................................................................... 58
16.7 Process control ................................................................................ 59
16.7.1 Sampling rate........................................................................... 59
16.7.2 Scan cycle................................................................................ 59
16.7.3 Output cycle ............................................................................. 60
16.8 Hysteresis ........................................................................................ 60
16.9 Operating parameters...................................................................... 60
17. Output modules.................................................................................... 61
17.1 Data cable........................................................................................ 61
17.2 Relay trigger modules...................................................................... 61
17.3 Analog outputs ................................................................................. 63
18. Trouble-shooting .................................................................................. 65
19. Declaration of conformity ..................................................................... 67
20. Annex................................................................................................... 69
20.1 Technical data .................................................................................. 69
20.2 Product overview ............................................................................. 70
20.3 Index ................................................................................................ 71
Your contact ..................................................................................................... 73

7
3. GENERAL
Congratulations on your purchase of this special ALMEMO®measuring instru-
ment from our latest V7 generation. Please note that this device is designed
exclusively for use with standard digital sensors (DIGI, Freq, Inp) and the new
D6 and D7 series. Thanks to the patented ALMEMO®plug the device configures
itself automatically and thanks to the menus and context-sensitive help windows
its operation should be fairly straightforward. The device can, however, be used
with a wide range of sensors and peripherals and offers many different special
functions. You are advised to take the time to carefully read these operating
instructions and the relevant sections in the ALMEMO®Manual and to properly
familiarize yourself with the way the new D7 sensors function and with the ex-
tended range of features the V7 device can now provide. This is the best way
to avoid operating and measuring errors and prevent damage to the device. To
help you find answers to your questions as quickly and easily as possible a
comprehensive index is provided at the end of these instructions and at the end
of the Manual.
3.1 Warranty
Each and every device, before leaving our factory, undergoes numerous quality
tests. We provide a manufacturer's guarantee, lasting two years from delivery
date, that your device will function trouble-free. Before returning your device to
us, please observe the advisory notes in Chapter 18, 'Trouble shooting'. In the
unlikely event that a device does prove defective and you need to return it,
please wherever possible use the original packaging materials for dispatch and
enclose a clear and informative description of the fault and of the conditions in
which it occurs.
This manufacturer's guarantee will not apply in the following circumstances:
Any form of unauthorized tampering or alteration inside the device
Use of the device in environments or conditions for which it is not suited
Use of the device with an unsuitable power supply and / or in conjunction
with unsuitable peripheral equipment
Use of the device for any purpose other than that for which it is intended
Damage caused by electrostatic discharge or lightning
Failure to properly observe these operating instructions
The manufacturer reserves the right to change the product's characteristics in
the light of technical progress or to benefit from the introduction of new compo-
nents.

3. General
8
3.2 Standard delivery
When you unpack the device please check carefully for any signs of transport
damage and ensure that delivery is complete.
- Measuring instrument ALMEMO®202-S or ALMEMO®204 with three AA
alkaline batteries
- These operating instructions
In the event of transport damage please retain the packaging material and in-
form your supplier immediately.
3.3 Waste disposal
The pictogram showing a waste bin crossed through means
that the product is subject to European Union regulations
covering segregated waste disposal. This applies both to
the product itself and to any accessories marked with the
same symbol. Disposal of any such item as unsorted do-
mestic waste is strictly forbidden.
•Please dispose of all packaging materials in accordance with the applicable
national waste management regulations.
•Please dispose of cardboard boxes, protective plastic packaging materials,
and all preservative substances separately and in the proper manner.
•The disposal of the device itself (also of device parts, accessories, and con-
sumables) is subject to the applicable national and local waste management
regulations and to the environmental protection legislation in force in the
country of use.
•Please dispose of all waste in the proper manner;
this applies in particular to all parts and substances that constitute a hazard
for the environment. This includes inter alia plastics, batteries, and recharge-
able battery packs.
•For the dispatch of such goods please wherever possible use the original
packaging materials.

9
4. SAFETY INSTRUCTIONS
DANGER
Danger to life and limb, risk of damage to equipment
Before starting to operate the device, please read the in-
structions carefully.
Please ensure that you comply with all general safety advice
and the special safety instructions included in other chap-
ters
Such risks may occur in the following circumstances:
-
Failure to heed the operating instructions and all the safety
notes these contain
- Any form of unauthorized tampering or alteration inside the de-
vice
-
Use of the device in environments or conditions for which it is
not suited
- Use of the device
with an unsuitable power supply and / or in
conjunction with unsuitable peripheral equipment
-
Use of the device for any purpose other than that for which it is
intended
- Damage caused by electrostatic discharge or lightning.
DANGER
Risk of fatal injury through exposure to dangerously high voltage
Such risks may occur in the following circumstances:
Use of the device with an unsuitable power supply and / or in
conjunction with unsuitable peripheral equipment
- Damage caused by electrostatic discharge or lightning
- Do not run sensor lines in the vicinity of high-voltage power ca-
bles.
- Before you touch any sensor lines, ensure that all static elec-
tricity has been discharged.
DANGER
Warning - explosive atmospheres or substances
In the vicinity of various fuels or chemicals there is a risk of ex-
plosion.
Do not use the device in the vicinity of blasting work or filling
stations.

4. Safety instructions
10
4.1 Special notes on use
•If the device is brought into the work-room from a cold environment
there is a risk that condensation might form on the electronics. In meas-
uring operations involving thermocouples pronounced changes in tem-
perature may cause substantial measuring errors. You are advised
therefore, before starting to use the device, to wait until it has adjusted
to the ambient temperature.
•Before using the mains adapter make sure that the mains voltage is
suitable.
•Be sure to observe the maximum load capacity of the sensor power
supply.
•Sensors with their own integrated power supply are not electrically iso-
lated from one another.
4.2 Handling batteries / rechargeable batteries cor-
rectly
When inserting batteries / rechargeable batteries ensure that the
polarity is correct.
If the device will probably not be needed for a relatively long pe-
riod of time or if the batteries are empty, the batteries should be
removed; this will prevent battery acid leaking onto the device
and damaging it.
Rechargeable batteries should be recharged as and when nec-
essary.
You should never attempt to recharge an ordinary (non-recharge-
able) battery; it may explode.
Batteries / rechargeable batteries must never be short-
circuited
or thrown onto the fire.
Batteries and rechargeable batteries are special wast
e and must
not be discarded as normal domestic waste.

11
5. INTRODUCTION
The measuring instruments ALMEMO
®
202-S and ALMEMO
®
204 are new mem-
bers in our family of unique measuring devices - all equipped with Ahlborn's pa-
tented ALMEMO
®
plug system. The intelligent ALMEMO
®
plug system - success-
fully tried and tested for over 20 years - offers decisive advantages when connect-
ing sensors and peripherals; since all parameters are stored in an EEPROM lo-
cated on the connector itself, there is no need to repeat programming. Any sensor
or output module can be connected to any ALMEMO
®
measuring instrument - all
in the same way.
Intelligent digital ALMEMO
®
sensors of the new D7 generation operating in con-
junction with our V7 measuring instruments overcome any lingering limitations
that may previously have affected the system -with the one exception that they
will not function on old V6 devices. These sensors, irrespective of the device's
quantities and ranges, operate as an autonomous measuring system with up to
10 channels covering completely new measurable variables, with all relevant con-
trol functions, calculation functions, or compensation values, and ranges up to 8
digits in size and at speeds of up to 1000 measuring operations per second
(mops). What is so special about this new generation is that, thanks to individual
sampling rates, both quick and slower but high-resolution variables can now very
easily be measured and recorded together. Individual sensor functions can be
parametrized via a menu stored in the plug itself. To facilitate identification the
quantity abbreviations and units have been extended to 6 digits and channel des-
ignation to 20 characters. This device has been specially conceived and designed
for digital sensors only. It can only be used therefore with digital standard sensors
(DIGI, Freq, Inp) and with all new D6 and D7 sensors. What is completely new
on V7 devices is the channel numbering system. Sensors and sockets are
counted from 0 to 9; this is followed, after a decimal point, by the channels, like-
wise counted from 0 to 9; i.e. the first sensor has channels 0.0 to 0.9, the second
has 1.0 to 1.9, etc.
Programming and functioning are virtually identical for all units. The following
points apply to all devices in the ALMEMO®measuring system; these are de-
scribed in detail in the ALMEMO®Manual which is included in delivery with each
device:
- Detailed explanation of the ALMEMO®system (Man., Chapt. 1)
- Overview of the device functions and measuring ranges (Man., Chapt. 2)
- Basic principles, operating instructions, and technical data for all sensors
(Man., Chapt. 3)
- Options for connecting your own existing sensors (Man., Chapt. 4)
- All analog and digital output modules (Man., Section 5.1)
- Interface modules RS232, USB, Ethernet, optic fiber (Man., Section 5.2)
- The whole ALMEMO®networking system (Man., Section 5.3)
- All functions and their operation via the interface (Man., Chapt. 6)

5. Introduction
12
- Complete list of interface commands with all the printouts (Man., Chapt. 7)
- The new V7 commands are described in a special V7 Manual supplementh.
The operating instructions you are now reading cover only those features and
controls that are specific to this device. Many sections refer to more detailed
descriptions in the Manual. (Manual. Section x.x.x).
5.1 Functions of the ALMEMO®202-S and
ALMEMO®204
ALMEMO®202-S and ALMEMO®204 measuring instruments have two or four
measuring inputs - suitable only - as previously stated - for digital ALMEMO®
sensors. The measuring possibilities opened up by the new D6 and D7 series
of digital sensors are virtually endless. The device can be operated via its inte-
grated softkey keypad with cursor block and its LCD graphics display. The dis-
play can be adapted via configurable sensor-specific menus to suit all applica-
tions. With the internal 8 megabyte memory or with connected memory plug (SD
card) a data logger function is realized. There are two output sockets which can
be used to connect ALMEMO®output modules, plug-in memory, analog output,
digital interface, trigger input, or alarm contacts. Multiple devices can be net-
worked together by simply connecting them via network cablen.
5.1.1 Sensor programming
The measuring channels are programmed, completely and automatically, via the
ALMEMO®plugs. However, the user can easily supplement or modify this pro-
gramming via the keypad or via the interface.
Measuring ranges
Although this device is limited to use with purely digital sensors it does provide
an elegant solution for numerous applications involving more complex sensors.
Sensors are already available for e.g. temperature (NTC, Pt100), all humidity
functions (dewpoint, mixture ratio, vapor pressure, enthalpy), atmospheric pres-
sure, flow (rotating vanes, hot-wire thermoanemometers), pressure and force,
current and voltage, also infra-red sensors, CO2and conductivity probes, color
temperature sensors, GPS receivers, and even a fully functioning weather sta-
tion. Adding to the number of suitable digital sensors is not a problem because
it is now no longer necessary (as it was previously) to adapt the measuring in-
strument accordingly. Each and every sensor is configured via its own internal
sensor menu.
Function channels
Maximum, minimum, and differential values of certain measuring points can be
programmed as function channels and can be processed like normal measuring
points.
Units
The units display (V5 two characters, D7 up to six characters) can be adapted
for each measuring channel in such a way that both the display and via interface

5. Introduction
13
always indicate the correct units, e.g. when a transmitter is connected. Conver-
sion between °C (Centigrade) and °F (Fahrenheit) is performed automatically.
Measured value designation
To help identify sensors an alphanumeric designation is also provided (V5 10
characters, D7 up to 20 characters). This designation appears in each meas-
ured value display, via interface and in the software.
Correction of measured values
The measured value on each measuring channel can be corrected both in terms
of zero-point and gain; this means that even sensors usually requiring initial ad-
justment (e.g. expansion, force, pH) can be interchanged freely. Zero-point cor-
rection and, partly at least, gain adjustment can be performed at the touch of a
button. Sensors with multi-point calibration can also be connected.
(see Manual 6.3.13).
Scaling
The corrected measured value on each measuring channel can also be further
scaled in terms of zero-point and gain based on the base value and factor. The
decimal point position can be set by means of the 'Exponent' function. Scaling
values can be calculated automatically by setting to zero and entering the nominal
setpoint or via the scaling menu.
Limit values and alarm
Per measuring channel two limit values can be set (one maximum and one min-
imum). In case of one of these limit values being infringed the relay output mod-
ules actuate the associated alarm contacts; these can be allocated individually
to specific limit values. Hysteresis is set by default to 10 digits; however, this can
be adjusted to any value between 0 and 99 digits.
Sensor locking
All sensor data stored in the EEPROM in the plug can be protected - by means
of a graduated locking function - against undesired access.
5.1.2 Measuring operation
For standard sensors up to four measuring channels are available; i.e. it is thus
also possible to evaluate double sensors, individually scaled sensors, and sen-
sors with function channels. All activated standard measuring channels are
scanned continuously at the sampling rate and the data acquired is shown in
the display. A D7 sensor has up to 10 channels and a sampling rate correspond-
ing to its own individual measuring speed; this sampling rate can be applied
individually over the new scan cycle.
Measured values
The display can show measured values either (in various menus, some user-
configurable) in two font sizes - or (in one of the user menus) in the form of a
bar chart. Measured values are acquired automatically with auto-zero and self-
calibration; however, they can also be corrected and scaled as and whenever
required. With most sensors a sensor breakage is detected automatically.

5. Introduction
14
Analog output and scaling
Each measuring point can be scaled by means of analog start and analog end
in such a way that the measuring range thus defined covers the full range of the
bar chart or of an analog output (2 V, 10 V, or 20 mA). At the analog output the
device can output the measured value from any measuring point or a pro-
grammed value.
Measuring functions
To achieve optimal measured value acquisition some sensors require certain
special measuring functions. The new intelligent sensors perform atmospheric
pressure compensation and temperature compensation internally and automat-
ically. With infra-red sensors the emissivity factor can be configured and set.
Measured value smoothing
Measured values of an unstable, fluctuating nature can be smoothed by taking
a sliding average over a number of values programmable from 2 to 99. The
averaging period will depend on the sampling rate and the number of active
channels. However, most D6 and D7 sensors are assigned their own averaging
period for all primary channels; this can be set via the sensor menu.
Maximum and minimum values
For each measuring operation the maximum value and minimum value are ac-
quired and saved to memory. These values can then be displayed, output, or
deleted from memory.
Average value
Manual averaging is available per channel over a particular period or cycle or
over a series of individual measuring operations.
Measured value memory
Up to 10 measured values can be saved manually. This data can then be shown
on the display or output via the interface.
5.1.3 Process control
To record the measured values from the connected sensors in digital form meas-
uring channel scanning must be performed continuously with measured value
output according to a time-based process control. A measuring operation can
be started and stopped by means of the interface, an external trigger signal, the
real-time clock, or by a specified limit value infringement. The standard cycle,
settable from 1 second up, ensures an even cyclic output. If a higher speed is
required, standard sensor values can be scanned and output at the sampling
rate; however, all sensors can now use the new scan cycle; this, if set to mini-
mum time, obtains measured values from each channel individually according
to its own actual measuring duration.
Date and time-of-day
Each measuring operation can be accurately logged using the real-time clock in
terms either of date and time-of-day or purely by actual measuring duration. For
the purposes of starting / stopping a measuring operation, the start / stop date
and time-of-day can be programmed via the interface.

5. Introduction
15
Output cycle
The output cycle can be programmed to any value from 1 second to 24 hours.
This function permits cyclic output of measured values to the interface or to the
memory and provides cyclic calculation of the average value.
Cycle factor
The cycle factor can be used to restrict data output from certain channels; this
may prove necessary in order to reduce excessive data flow especially while
measured data is being saved.
Averaging over measuring point scans
The measured values from measuring point scans can be averaged either over
the whole fixed measuring period or over the specified cycle. These average
values can then be output and saved on a cyclic basis to function channels pro-
vided for this purpose.
Sampling rate
All standard digital channels (DIGI and D6) are scanned continuously at the set
sampling rate of 10 measuring operations per second (mops). This rate can
also be programmed to 2.5 mops.
Scan cycle
With the ALMEMO®202-S and ALMEMO®204 there is also the superordinate
scan cycle, which acquires all standard channels and D7 channels whenever
one of these delivers a new current measured value. Recording can be accel-
erated if measured values thus acquired are output via the interface and / or to
a plug-in memory immediately.
Measured value memory
With the ALMEMO®202-S and ALMEMO®204 data logger, all measured values
can be stored manually or automatically in a cycle in an EEPROM. The standard
storage capacity is 8 Megabyte, sufficient for up to 400,000 measured values.
The memory organization can be set as linear or ring memory. Output is via the
interface. A selection by time section or number is possible.
All devices in the ALMEMO®204 series can, by fitting an external plug-in
memory and micro-SD card, be upgraded to a high-capacity data logger. Using
this external memory (available as an accessory) files can be read out very
quickly via any standard card reader.
Control ports
A relay trigger analog adapter can be used to provide up to ten output relays,
and, as option, up to four analog outputs and two trigger inputs.

5. Introduction
16
Operation
All measured values and function values can be displayed in different menus on
the dot-matrix LCD screen. User menus can be individually configured for your
specific applications from a range of nearly 50 functions, texts, lines, and empty
lines. There are six keys (four of them softkeys) for operating the device. These
can also be used to fully program the device, sensors, and process control.
Output
All data logs, menu functions, saved measured values, and stored program pa-
rameters can be output to any peripheral equipment. Using the appropriate in-
terface cable any of interfaces RS232, USB, or Ethernet can be used. To ac-
commodate the variable data quantities the interface protocol has been
changed so that data is now output in table format only; this can then as required
be processed directly using any standard spreadsheet program.
Networking
All ALMEMO®devices can be individually addressed and can be networked to-
gether by simply linking them up via network cable. However, old V5 / V6 de-
vices and the new V7 devices use different protocols and must therefore be
operated via different COM ports.
Software
Each ALMEMO®Manual is accompanied by the ALMEMO®Control software
package, which can be used to configure the measuring instrument and user
menus, to program the sensors, and to read out from the measured value
memory. Using the integrated terminal, measuring operations can also be per-
formed online. The WINDOWS®software package Win-Control is provided for
measured value acquisition from networked devices, for graphical presentation,
and for more complex data processing.

17
6. PUTTING INTO SERVICE
Sensor connection Connect sensors to sockets M0 to M1 (1) s. 8.
Power supply via batteries or mains adapter at socket DC (3) s. 7.1, 7.2
To switch ON Press ON / PROG (5) once and release s. 7.5
Automatic display of last measuring menu s. 11.
For menu selection
press key: <MENU>
On / off display illumination: <ON> / <OFF>
Select sensor list s. 9.1 menu <F> : ▲ / ▼ ...
Call up a menu: ►or. PROG
Select a sensor (s. 10) ▲ / ▼ ...
Display sensor: <M ◄◄ >
Select a measuring channel (s. 11.1.1)
<M> : ▲ / ▼ ...
All channels on the connector or those functions needed
for measured value calculation are displayed.
Data logger functions: (s. 11.4)
Select Menu U2 data logger : <MENU> , ▼..,►
Select memory cycle PROG , ▲/ ▼...
Using the scan cycle:
For V6 set 'scan time': <SCANT>
For D7 set 'minimum time': <MIN>
Return to output cycle (00:01:00): <RESET>
Enter the cycle (s. 9.5):PROG , ▲/ ▼, ►
..
Terminate programming mode: < ESC>
Start / stop measuring: <START> -<STOP>
Output via an interface:
-Connect peripheral equipment via data cable to socket A1 (2) s. Man. 5.2
Select free memory : PROG , ▼...
Output memory s. 14.5.6 < PMEM> or command ´P04´ from the computer
Delete memory content s. 14.5.6 < CMEM > or command ´C04´ from the computer

18
7. POWER SUPPLY
Power can be supplied to the measuring instrument in any of the following ways
:
Three AA alkaline batteries (included in delivery)
Mains adapter, 12 V, min. 1 A, with ALMEMO®plug ZA1312-NAx
Power supply cable, electr. isolated 10 to 30 VDC, 0.25 A ZA2690-UK
USB data / power cable 9 V, 0.2 A ZA1919-DKU5
Our product spectrum covers all the appropriate accessories.
7.1 Battery operation and supply voltage monitor-
ing
The device is normally powered by three AA alkaline batteries. At a current
consumption of on average 30 mA, these should last for an operating time of
approx. 100 hours. However, if the display illumination is left switched on, this
will be reduced to approx. 50 hours. Since this device operates exclusively with
active sensors, their current consumption must also be considered. The current
operating voltage can be checked in the Info menu; this gives you a basis for
estimating the remaining operating time. (s. 10) As soon as the remaining bat-
tery capacity drops to approx. 10 %, the battery symbol ´´µµµµµµµµµ¶ will appear in the
status bar or softkey bar of the display and start to flash. If the batteries dis-
charge completely, the device will switch off automatically as soon as battery
capacity drops to approx. 3 V; any parameters set will be saved. (s. 7.6) To
replace used batteries first switch the device off and then unscrew the cover of
the battery compartment located on the rear of the device. (6) When inserting
fresh batteries ensure that their polarity is correct.
7.2 Mains operation
To power this device from an external source preferably use mains adapter ZA-
1312-NAx (12 V / min. 1 A); connect this to the DC socket. (3) Please ensure
that the mains voltage is correct. The sensor voltage rises to approx. 12 V.
7.3 External DC voltage supply
The DC socket can also be used to connect another DC voltage, 6 to 13 V (min-
imum 200 mA). (3) It can be connected using ALMEMO®plug ZA-1312-FS8. If,
however, the power supply has to be electrically isolated from the transducers
or if a larger input voltage range (10 to 30 V) is required, then electrically isolated
supply cable ZA-2690-UK must be used. It will then be possible to use the
measuring instrument in a 12-volt or 24-volt on-board supply system. A practical
alternative is USB data / power cable ZA-1919-DKU5; this provides simultane-
ously a data interface to the computer and power supply. (not electrically iso-
lated)

7. Power supply
19
7.4 Sensor supply
At the terminals + (plus) and - (minus) in the ALMEMO®plug there is a sensor
supply voltage of 6 / 9 / 12 V (self-healing fuse, total current 500 mA); this is set
automatically depending on the minimum sensor supply. With a 12 V supply the
sensor supply voltage will generally also increase to 12 V.
7.5 Switching ON / OFF, reinitialization
To switch the device ON press and release ON PROGrlocated in the middle of
the cursor block. (5) The measuring menu most recently selected always ap-
pears in the display first. To switch OFF press and hold down the same key(s)
ON PROGr. After the device is switched off the real-time clock continues to run
and all saved values and settings are retained intact. (s. 7.6) If interference (e.g.
electrostatic, battery failure) causes the device to behave abnormally, it can be
reinitialized. To activate a reset press and hold down key F1 rwhen switching
on. To return all device programming (including device designation, user menus,
process control, etc.) to the factory default settings press and hold down key F2
rwhen switching on. In so doing certain parameters will be lost or returned to
their defaults : Language: German, Illumination: OFF, Device address: 00, Hys-
teresis: 10, Sampling rate: 10 mops.
Sensor programming in the ALMEMO®plugs will remain unaffected.
7.6 Data buffering
The sensor's programming is stored in the EEPROM on the sensor plug; the
device's calibration values and programmed parameters are stored in the
EEPROM on the instrument itself; in the event of failure both will be retained
intact. Date and time-of-day settings and the individual value memory are re-
tained intact if the device is just switched off or when the batteries are changed
- so long as the batteries have a voltage of approx. 2.7 V.

20
8. CONNECTING SENSORS / TRANSDUCERS
Only digital ALMEMO®sensors can be connected at input sockets M0 to M1
resp. M0 to M3 (1) on measuring instruments ALMEMO®202-S and ALMEMO®
204, i.e. only standard sensors with DIGI, Freq, or Inp, and all new D6 and D7
sensors. All standard sensors with an ALMEMO®plug usually have the meas-
uring range and units already programmed and can thus be connected to any
input socket without further adjustment. A mechanical coding system ensures
that sensors and output modules can only be connected to the correct sockets.
All ALMEMO®plugs incorporate two snap-lock levers; these snap into position
as soon as the plug is inserted into the socket, thus preventing unintended dis-
connection if the cable is pulled accidentally. To withdraw the plug both these
levers must first be pressed in at the sides.
8.1 Standard sensor (V5)
ALMEMO
®
V5 sensors are housed in a light-gray case. The source of their intel-
ligence is an 2-KB EEPROM integrated in the sensor plug, in which all channel
settings are stored; the device is thus programmed completely as soon as such a
sensor is connected. With the newer V6 version incorporating a 4-KB EEPROM
(E4) multi-point calibration can be performed on the sensor. Digital sensors used
for the quantities - frequency, pulse, or DIGI - incorporate a microcontroller, which
transfers digital signals to the device via an I2C bus. Measured values are pro-
cessed in synchrony with the sampling rate and at a resolution of maximum
±65000 all in the device.
8.2 D6 sensors
ALMEMO®D6 sensors are housed in a partly light-gray, partly dark-gray case;
they are completely autonomous measuring modules not only for digital but also
for analog sensors; they can, independently of the device, handle new measuring
ranges with special measured value processing and various forms of compensa-
tion. As regards measured value processing D6 sensors are fully compatible with
standard sensors - except for multi-point calibration and smoothing; however, on
this V7 device, quantity configuration and parametrization can be performed via
the 'Sensor configuration' menu or using a USB adapter cable directly on the PC
(s. 15.10).
8.3 D7 sensors
ALMEMO®D7 sensors are housed in a dark-red case; they too are completely
autonomous measuring modules for digital and for analog sensors - but offer
substantially enhanced properties. The sampling rate can be set from 1 milli-
second up to several minutes with a resolution up to 8 digits. The number of
channels has, thanks to a new numbering scheme, been extended up to 10 per
sensor and up to 10000 per device. Channel designations can be up to 20
characters and units up to six characters in length. With D7 sensors up to four
primary channels can also be smoothed at the same time internally over the