Ahlborn ALMEMO 2390-5 User manual

Operating instructions
Multifunction measuring instrument
ALMEMO®2390-5
with data logger option
V1.3
10.10.2005
ALMEMO2390-5 1

Operating instructions
Multi-function measuring instrument
ALMEMO®2390-5
with data logger option
With supplementary reference to the ALMEMO®Manual
Table of contents Page
1 INTRODUCTION 4
1.1 Functions 4
1.2 Operating controls 9
2 PUTTING INTO SERVICE 11
3 POWER SUPPLY 12
3.1 Battery / rechargeable battery operation 12
3.2 External voltage supply 13
3.3 Switching ON / OFF, retaining stored data, reinitialization 14
3.4 Sensor supply 14
4 CONNECTING THE TRANSDUCERS 15
4.1 Transducers 15
4.2 Measuring inputs and additional channels 15
5 DISPLAY AND KEYPAD 17
5.1 Display 17
5.2 Function selection and activation 19
5.3 Keypad 21
5.4 Data input 22
6 MEASURING OPERATIONS 23
6.1 Measuring point scanning and measuring point display 23
6.1.1 Selecting the measured value and the measuring point 23
6.1.2 Differential measurement 24
6.1.3 Maximum and minimum value memories 24
6.2 Measured value correction and compensation 24
6.2.1 Setting the measured value to zero 25
6.2.2 Sensor adjustment, zero-point, and gain 25
6.2.3 Entering a setpoint 26
6.2.4 Cold junction compensation 27
6.2.5 Atmospheric pressure compensation 28
2 ALMEMO2390-5
Table of contents

6.2.6 Temperature compensation 28
6.3 Measuring point scans and data output 29
6.3.1 Once-only measuring point scan 29
6.3.2 Cyclic measuring point scan 29
6.3.3 Output formats for measured value lists 30
6.3.4 Manual data output 31
6.4 Averaging 32
6.4.1 Smoothing out measured values by means of a sliding average 32
6.4.2 Averaging mode 32
6.4.3 Averaging over the time from start to stop 33
6.4.4 Averaging over single measurements 34
6.4.5 Volume flow measurement 35
6.4.6 Cyclic averaging 36
6.4.7 Averaging over several measuring points 37
6.5 Measured value memory (option S) 37
6.5.1 Memory connector 37
6.5.2 Measured value recording 38
6.5.3 Measured value output 39
6.5.4 Sleep mode 40
7 SENSOR PROGRAMMING 41
7.1 Selecting a measuring point 41
7.2 Locking the sensor programming 41
7.3 Limit values 42
7.4 Correction values 42
7.5 Scaling, decimal point setting 43
7.6 Changing the units 44
7.7 Selecting the measuring range 44
7.7.1 Special meas. ranges, linearization, multi-point calibration 48
8 ANALOG OUTPUT 49
8.1 Scaling 49
9 DEVICE PROGRAMMING 50
9.1 Date and time-of-day 50
9.2 Baud rate, data format 50
9.3 Device address and networking 51
10 trouble-shooting 52
ALMEMO2390-5 3
Table of contents

1. INTRODUCTION
The multi-function measuring instrument ALMEMO®2390-5 is a new member
in our family of unique measuring devices - all equipped with Ahlborn GmbH’s
patented ALMEMO®connector system. The intelligent ALMEMO®connector of-
fers decisive advantages when connecting sensors and peripherals because all
parameters are stored in an EEPROM on the connector itself; repeat program-
ming is thus no longer necessary.
All sensors and output modules can be connected to all ALMEMO®measuring
instruments - all in the same way. Programming and functioning are identical
for all units. The following points apply to all devices in the ALMEMO®measu-
ring system and are described in detail in the ALMEMO®Manual supplied with
each device.
Detailed description of the ALMEMO®system (Manual, Chapter 1)
Overview of the device functions and measuring ranges (Manual, Chap. 2)
Basic principles, operating instructions, and technical data for all sensors
(Manual, Chapter 3)
Options for connecting your own existing sensors (Manual, Chapter 4)
All analog and digital output modules (Manual, Section 5.1)
Interface modules RS232, optic fiber, Ethernet, Bluetooth (Manual, Chap. 5.2)
The entire ALMEMO®networking system (Manual, Section 5.3)
All functions and their operation via the interface (Manual, Chapter 6)
Complete list of interface commands with all the printouts (Manual, Chap. 7)
The operating instructions you are now reading cover only those features and
controls that are specific to this device. Sections dealing with operation via the
keypad often refer to a more detailed explanation in the Manual (Manual, Secti-
on x.x.x).
1.1 Functions
The multi-function measuring instrument ALMEMO®2390-5 has three electri-
cally isolated measuring inputs suitable for all ALMEMO®sensors. The measu-
ring possibilities are virtually unlimited; there are 12 channels in the sensor con-
nectors and 4 device-internal function channels - with over 70 measuring ran-
ges and genuine differential measuring features. There are 2 output sockets
which can be used to connect any ALMEMO®output modules, e.g. analog out-
put, digital interface, trigger input, or alarm contacts. Several devices can be
networked together by simply interconnecting them over network cables. The
measuring instrument incorporates a keypad and an 8½-character LCD. The
measuring instrument is also available with a data logger option with an internal
32-KB memory or external connectors with up to 256 KB capacity (50000 mea-
sured values). A wide range of functions can be activated either automatically
or individually, e.g. for evaluating all sensors, for process control, and for uni-
versal data output. There is also a range of special functions accessible only
via the interface.
4 ALMEMO2390-5
Functions

SENSOR PROGRAMMING
The measuring channels are automatically programmed via the ALMEMO®sen-
sor connectors. However, the user can easily supplement or modify this pro-
gramming via the keypad or via the interface.
Measuring ranges
Appropriate measuring ranges are available for all sensors with a non-linear
characteristic, e.g. 10 thermocouple types, Ntc and Pt100 sensors, infrared
sensors, and flow sensors (rotating vanes, thermoanemometers, Pitot tubes).
For humidity sensors additional function channels are available for calculating
humidity variables such as dew point, mixture ratio, vapor pressure, and enthal-
py. Even complex chemical sensors are supported. Measured values from
other sensors can also be acquired using the voltage, current, and resistance
ranges with individual scaling in the connector. Existing sensors can also be
used - so long as the appropriate ALMEMO®connector is connected via its
screw terminals. For digital input signals, frequencies, and pulses, adapter
connectors are available with an integrated microcontroller. It is thus possible to
connect virtually any sensor to any ALMEMO®measuring instrument and to
change sensors without the need for any extra settings.
Function channels
Maximum, minimum, and average values, differential measured values, volume
flow, and wet bulb globe temperature (WBGT) can be programmed as function
channels and further processed and printed out just like normal measuring
points.
Units
The 2-character units display can be adapted for each measuring channel so
that both the display and the printout always indicate the correct units, e.g.
when a transmitter is connected. Conversion between °C and °F is performed
automatically.
Measured value designation
Each sensor is identified by means of a 10-character alphanumeric name. This
name, entered via the interface, will subsequently appear in the printout or, if
evaluated by computer, on the screen.
Measured value correction
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 in-
itial adjustment (expansion, force, pH) can be freely interchanged. Zero-point
correction and, partly at least, gain adjustment can be performed at the touch of
a button.
Scaling
The corrected measured value on each measuring channel can also be further
scaled in terms of zero-point and gain - using the base value and factor. The
decimal point position can be set by means of the exponent function. By setting
to zero and entering the nominal value the scaling values can be calculated au-
tomatically.
ALMEMO2390-5 5
Functions

Limit values and alarm
Per measuring channel two limit values can be set (1 maximum and 1 mini-
mum). In the event of one of these limit values being exceeded relay output
modules actuate the appropriate alarm contacts. Hysteresis is set by default to
10 digits but can also be adjusted. The exceeding of a limit value can also be
used to start or stop measured value recording and data logging.
Sensor locking
All sensor data stored in the connector EEPROM can be protected by means of
a graduated locking function against undesired access.
MEASUREMENT
For each transducer up to four measuring channels are available; i.e. it is also
possible to evaluate double sensors, individually scaled sensors, and sensors
with function channels. It is possible using the keypad to move from one mea-
suring channel to the next successively forwards or backwards. The selected
measuring point is scanned at a conversion rate of 2.5 or 10 measuring operati-
ons per second; the measured value is calculated and output to the display
and, if available, to an analog output.
Measured value
The measured value for the selected measuring point is shown continuously
with auto zero and, optionally, with measured value correction or scaling.
With most sensors, sensor breakage is detected automatically (except for con-
nectors with shunt, dividers, or additional electronics).
Measuring functions
With some sensors, in order to achieve optimal measured value acquisition,
certain special measuring functions are required. Cold junction compensation
is provided for thermocouples; temperature compensation is provided for dyna-
mic pressure, pH, and conductivity probes; and atmospheric pressure compen-
sation is provided for humidity sensors, dynamic pressure sensors, and O2
sensors. On infrared sensors the parameters for zero-point correction and gain
correction are used as the background temperature and the emissivity factor.
Analog output and scaling
The displayed measured value can, by means of analog start and analog end,
be scaled in such a way that the measuring range thus defined covers the full
analog output range (2 V, 10 V, or 20 mA).
Maximum and minimum values
For each measuring operation the maximum value and minimum value are
acquired and saved to memory. These values can then be displayed, printed
out, or deleted from memory.
Average value of a channel
Averaging can be performed per selected channel for the purposes of signal
smoothing, either over a certain period or over single measurements.
6 ALMEMO2390-5
Functions

Volume flow measurement
For all flow sensors not only the functions for averaging are provided but also
functions for entering the cross-section and diameter of ventilating channels
and for calculating the volume flow. The average flow velocity can be deter-
mined roughly by scanning the whole cross-section or exactly by means of net-
work measurements according to DIN. For dynamic pressure probes both tem-
perature compensation and atmospheric pressure compensation are provided.
Under the appropriate environmental conditions these values can be either
entered manually or measured automatically.
PROCESS FLOW PROGRAMMING
To record the measured values from all connected sensors in digital form a cy-
clic measuring point scan with a time-based process flow control is required.
This feature involves the real-time clock, the print cycle, and, if high-speed
processing is required, the conversion rate itself. The measuring operation can
be started and stopped via the keypad, the interface, an external trigger signal,
or by exceeding a specified limit value.
Date and time-of-day
Each measuring operation can be logged either using the real-time clock with
the date and time-of-day function or purely in terms of the actual measuring ti-
me.
Print cycle
The print cycle can be programmed to any value between 00:00:01 (1 second)
and 59:59:59 hh:mm:ss. This function permits cyclic saving and output of mea-
sured values to the interfaces and cyclic calculation of the average and sum of
values.
Print cycle factor
The print cycle factor can be used to limit data output from particular channels;
this may prove necessary in order to reduce excessive data flow.
Averaging over measuring point scans
The measured values obtained by scanning measuring points can be averaged
either over a number of measuring points or over one particular measuring
point either for the total measuring time or over the print cycle time. Function
channels are provided for the cyclic output of such average values.
Conversion rate
With ALMEMO®devices all measuring points can be continuously scanned with
a conversion rate of either 2.5 or 10 measuring operations per second. It is al-
so possible to output all measured values to the interface.
Measured value memory (option S)
Measured values can be saved manually, cyclically, or at the selected conversi-
on rate to an internal 32-KB EEPROM (with sufficient capacity for up to 6000
measured values). Each measuring operation can also be started and stopped
ALMEMO2390-5 7
Functions

automatically according to date and time-of-day. The memory can be organi-
zed and configured in linear or ring form. As an alternative storage medium ex-
ternal ALMEMO®connectors are also available with an EEPROM of either 128
KB capacity (sufficient for 25000 measured values) or 256 KB capacity (suffi-
cient for 50000 measured values). Data recordings can be easily and conveni-
ently managed for each such connector and read out from the computer whe-
never needed via a separate read interface. Or alternatively each measuring
operation can be assigned a number. For output via the interface it is possible
to specify a selection according to either the time interval or the number as-
signed to the measuring operation.
Control outputs
It is possible via the interface to individually address up to four external output
relays and one analog output.
Output
All measured values and programming parameters can be accessed via the
LCD. Interfaces for RS232, RS422, Centronics, and Ethernet are provided via
the appropriate interface cables. All data logs, saved measured values, and
programming parameters can be output to any peripheral equipment. Measu-
red data can be output in list, column, or table format. Files in table format can
be processed directly using any standard spreadsheet software. The print hea-
der can be programmed specifically to the company or application.
Networking
All ALMEMO®devices are adressable and can be easily networked by simply
linking them up via the appropriate network cables or, over longer distances, via
RS422 network distributors.
Software
Each ALMEMO®device is accompanied by the AMR-Control software package,
which can be used to configure the measuring instrument, to program the sen-
sors, and to read out from the measured value memory. It is also possible
using the integrated terminal to perform measuring operations online and to sa-
ve the measured values to PC. The WIN-Control software package for WIN-
DOWS®is provided for the purposes of measured value acquisition via networ-
ked devices, for graphical presentation, and for more complex data processing.
8 ALMEMO2390-5
Functions

1.2 Operating controls
(1) ON/OFF-switch
up ON
down OFF
(2) Measuring inputs M0, M1, M2
M0, M1, M2 for all ALMEMO-sensors
M3 Function channel differential
M10 .. M33 Additional channels
(3) Output sockets A1, A2
A1 V24-interface (ZA 1909-DK5/DKL)
Ethernet (ZA 1945-DK)
RS 422 (ZA 5099-NVB)
Relay-trigger-cable (ZA 1000-EAK)
Analog output 1 (ZA 1601-RK)
A2 Memory connector (ZA 1904-SS)
Network cable (ZA1999-NK5)
Trigger input (ZA 1000-ET)
Relay output (ZA 1000-EGK)
Analog output 2 (ZA 1601-RK)
(4) Socket DC
Mains adapt. (ZB 2290-NA, 12V, 200mA)
Cable electr. isolat. (ZB 2290-UK, 10-30V)
(5) LCD display (see below)
(6) Function keys (see below)
(7) Battery compartment (rear of dev.)
9-volt alkaline-manganese battery
(6F22) (space for reserve battery)
(5) LCD display
(a) Symbols for operating states
Battery voltage < 7 V
BAT
▲ CORR Measured value correct.
▲ Averaging
M
▲ START Measuring operat. started
▲ MEM Measured value memory
▲ COM Measured value output
▲ ALARM Limit value exceeded
▲ FFunction
(b) 6½ x 7 segment display for:
measuring point, measured value,
measuring range, measured values,
programming parameters, cycles, da-
te, time-of-day
(c) 2 x 16 segment display for:
units for measured value,
function abbreviations
ALMEMO2390-5 9
Operating controls
23
BAT
(1) (3)
(4)
(5)
(6)
(7)
(2)
CORR M START COM
MEM ALARM F
a
bc

(6) FUNCTION KEYS
PROG, +/-,▲▼, Input of programming parameters
▲
PROG, CLEAR Clear data, set measured value to zero
PROG, ▼, PROG Adjust measured value
M ▲Select measured value, measuring point
START/STOP Start and stop a measuring operation
MANU/PRINT Manual measuring point scan, data output
FUNCTION Select function(s)
Maximum value (Hi) MH
Minimum value (Lo) ML
Average value AV +
Number of average value C+
Averaging mode AM
Level of smoothing DG
Diameter standardized DN °
Cross-section area CS °
Atmospheric pressure mb
Temperature compensation TC
Memory free MF #
Memory time MT #
Cycle CY
Time-of-day TM
Date DA
Start time ST #
Start date SD #
End time ET #
End date ED #
Baud rate, output format BR
Device adress A
Range R
Functions are activated by:Locking mode LM
All functions are activated by FUNKTION Maximum limit value (Hi) LH *
pressing and holding down the FUNCTION key; Minimum limit value (Lo) LL *
each function can be activated Analog output - start AS *
individually by interface command. Analog output - end AE *
Standard (switch ON with CLEAR key) Base value BA *
#Option S data logger Factor FA *
* Locking mode (not locked) Exponent EX *
+Averaging mode programmed Zero piont correction ZC *
° Measuring range ´Flow´ Gaint correction SC *
^ Infrared sensors (IR-flag) Ambient temperature AT ^
Emissivity factor EF ^
Display mode (language) DM
10 ALMEMO2390-5
Operating controls

2. PUTTING INTO SERVICE
1. Connect transducer to sockets M0 to M2 (2); (see Section 4).
2. Ensure that the power supply is provided via 9-volt battery or mains
adapter; (see Sections 3.1, 3.2).
3. To switch ON, push slide switch (1) located on left side of device upwards;
(see Section 3.3).
4. Displaying the measured values
Select MEASURED VALUE function by pressing the key M▲(6).
Select measuring channels by pressing key M▲and read out measured
values; (see Section 6.1.1).
5. Connect the cyclic measured value output to the printer or to the
computer. Connect the peripheral device via interface cable to socket A1;
(s. Manual, Sec. 5.2). On the peripheral device set 9600 bauds, 8 data bits,
1 stop bit, no parity; (see Section 9.2). If necessary enter the current
date and time-of-day; (see Section 9.1). Select CYCLE function ´ZY´ by
pressing the FUNCTION key and program the cycle; (see Section 6.3.2).
Select the output format in the BAUD RATE function ´BR´ by pressing keys
PROG, ▲.., PROG, ESC; (see Section 6.3.3).
Start and stop cyclic measuring point scanning by pressing the
START/STOP key; (see Section 6.3.2).
6. Saving measured values (only possible with option S)
Select CYCLE function ´ZY´ by pressing the FUNCTION key and program the
cycle; (see Section 6.3.2).
If necessary enter the current date and time-of-day; (see Section 9.1).
Start and stop measured value recording by pressing the START/STOP key;
(see Section 6.3.2).
Output data from memory to the printer or to the computer.
Connect the peripheral device via interface cable to socket A1; (see
Manual, Section 5.2). On the peripheral device set 9600 bauds, 8 data bits,
1 stop bit, no parity; (see Section 9.2).
Select the output format in the BAUD RATE function ´BR´ by pressing the keys
PROG, ▲.., PROG, ESC; (see Section 6.3.3).
In the function ´SF´ output measured values by pressing the MANU/PRINT
key; (see Section 6.5.3).
7. Evaluating a measuring operation
Select the function MAXWERT ´MH´ or MINWERT ´ML´ by pressing the FUNCTION
key and call up the maximum and minimum values; (see Section 6.1.3).
ALMEMO2390-5 11
Putting into service

3. POWER SUPPLY
As power supply for the measuring instrument there are the following possibili-
ties: 9-volt batteries IEC 6F22 ZB 2000-B9
9-volt rechargeable battery pack, same
with charger integrated in the connector ZB 2000-A9, ZB 2000-LS
mains adapter 12 V / 200 mA ZB 2290-NA
external power supply, connecting cable ZB 2290-UK
Our product spectrum includes all the appropriate accessories.
3.1 Battery / rechargeable battery operation
Use only alkaline-manganese batteries, type IEC 6F22. At a current consump-
tion of around 10 mA, these last for an operating time of approx. 35 hours. If
sensors or modules also requiring power are connected, this operating time will
be accordingly shorter.
Inserting the batteries: The battery compartment (7) is located underneath
the device.
1. Press on the spot marked with an arrow and at the
same time pull in the direction the arrow indicates
(as shown in the illustrations).
2. Connect the battery using one of the battery clips.
Accidental reverse polarity is prevented by the sha-
pe of the connectors.
3. By adding a second battery you can double the
available operating time.
Battery check : If the battery symbol in the display lights up, this means
that the battery will last for approximately another 4
hours only. (Supply voltage <7 V)
In the event of the battery voltage falling below 6 volts,
the display shows the message ‘LobAt’. In this event
the battery must be removed immediately. This pre-
vents the battery from leaking and thus damaging the
device.
You can check the current battery voltage and estimate the bat-
tery’s remaining useful life by applying a measuring channel spe-
cially to ‘Ubat’ (battery voltage).
12 ALMEMO2390-5
Power supply

Tips on how to handle batteries correctly:
Never leave used dead batteries in the device !
If the device is likely to be unused for a relatively long time, remove the
batteries !
A leaking battery represents a health hazard and may also destroy the de-
vice. Use only leak-proof batteries !
Spent batteries are classified as special waste and must be disposed of in
an environmentally acceptable way. Take spent batteries back to your
dealer or dispose of them in your local battery collection container !
Rechargeable battery operation:
Instead of the standard batteries you can use rechargeable battery packs.
Rechargeable batteries are of lower capacity, 110 mAh, and provide an opera-
ting time of only 16 hours. If sensors or modules also requiring power are con-
nected, this operating time will be accordingly shorter. From our range of ac-
cessories we recommend the 9-volt rechargeable battery pack with a charger
integrated in the connector (order no. ZB 2000-LS).
Tips on how to handle rechargeable batteries correctly :
Rechargeable batteries, when you first receive them, are not charged.
You must first of all charge them to full capacity.
Attempting to recharge NiCd cells that are only partly discharged will not
restore them to full capacity. For this reason use the device until the
rechargeable battery pack is nearly totally discharged and then recharge
it completely. This will significantly prolong the useful life of your rechar-
geable batteries.
Even fully charged batteries not being used or left in storage will slowly
discharge; they should therefore be checked at least once per month and
if necessary recharged in order to ensure that they are not damaged as a
result of critically low discharge.
3.2 External voltage supply
On the right side of the device there is a socket (4) for connecting an external
power supply. In our range of accessories we offer a mains adapter (12 V /
200 mA) (order no. ZB 2290-NA). Or, alternatively, you can use some other
DC power source (7 to 13 V). The power source is connected by means of a
low-voltage connector (NES1 as per DIN 42323, center pin to minus).
If, however, the power supply has to be electrically isolated from the transdu-
cers or if a larger input voltage range is required, then electrically isolated
supply cable ZB 2290-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.
If a battery is connected, this will, in the event of a voltage drop
below 9 volts, take over as power supply.
ALMEMO2390-5 13
Power supply

3.3 Switching ON / OFF, retaining stored data, reinitialization
The ON / OFF slide switch (1) located on the left side of the device has two
switch positions :
To switch ON, push the slide switch (1) located on the left side of the device
upwards. - up : ON
To switch OFF, push the slide switch down - down : OFF
Retaining stored data
When the device is switched off, all sensor parameters and most device para-
meters remain stored in EEPROMs. The real-time clock continues to run and
the device status is retained so long as the 9-volt battery remains charged with
at least 6 volts. It is important when exchanging batteries to first connect the
new battery to the 2nd battery clip and only then withdraw the old battery. If the
old battery was already totally discharged, you will have to perform a reinitializa-
tion.
Reinitialization
The device should be reinitialized in the following circumstances : if the battery
supply is interrupted, if interference (e.g. electrostatic or incorrectly connected
peripherals) causes the device to behave abnormally, or if you need to cancel
incorrect programming.
You can activate this reset by pressing key CLEAR when switching ON. This
has the effect of clearing or resetting to their default values all measured data,
date, time-of-day, and also all internal setting data, e.g. cycles, conversion rate,
atmospheric pressure, and function key assignment. However, this does not
affect the programming of the sensors in the ALMEMO®connectors.
The reset function is not the only one that can be activated when switching ON;
other useful special functions can be activated at this stage by pressing the ap-
propriate keys :
Switching ON with various keys pressed:
CLEAR: This activates a reset
PROG und FUNCTION: This sets the locking mode for the selected measuring
point to level 3; this applies only temporarily until you
switch OFF again; (see Sections 6.2.1/2).
MANU: This changes the meas. point numbering mode;(Sec. 4.2)
START/STOP: This displays the device version
3.4 Sensor supply
The battery voltage or external voltage needed to supply the sensors is provi-
ded at the + and - terminals in the ALMEMO®connector. There are also spe-
cial connectors available for 12-volt, 15-volt, or 24-volt DC and for 5-volt and
2.5-volt reference voltages; (see Manual, sections 4.2.5/6). It is important to
ensure that the total current consumed by the sensors does not exceed 70 mA!
14 ALMEMO2390-5
Power supply

4. CONNECTING THE TRANSDUCERS
Virtually any ALMEMO®sensor can be connected to any of the ALMEMO®input
sockets M0 to M2 (2). To connect your own existing sensors you simply need
the appropriate ALMEMO®connector.
4.1 Transducers
The ALMEMO®Manual includes detailed descriptions of the comprehensive
range of ALMEMO®sensors (see Manual, Chapter 3) and of how to connect
your own existing sensors to ALMEMO®instruments (see Manual, Chapter 4).
All standard sensors with an ALMEMO®connector usually have the measuring
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.
Each ALMEMO®connector also incorporates two snap-lock levers; these snap
into position as soon as the connector is inserted into the socket, thus preven-
ting unintended disconnection if the cable is accidentally pulled. To withdraw
the connector, both these levers must be pressed in at the sides.
4.2 Measuring inputs and additional channels
Measuring instrument ALMEMO 2390-5 has three input sockets M0, M1, M2 (2)
to which initially measuring channels M0, M1, M2 are allocated. ALMEMO®
sensors can, however, if necessary, provide up to four channels. The additional
channels can be used in particular for humidity sensors with four measuring va-
riables (temperature / humidity / dew point / mixture ratio) or for function chan-
nels. Each sensor can if necessary be programmed with several measuring
ranges or scaling settings; and two or three sensors, if pin assignment so per-
mits, can be combined in a single connector (e.g. rH / Ntc, mV / V, mA / V,
etc.).
Measuring point numbering
Each additional measuring channel in a connector lies one level higher. In this
new series the levels are now numbered in standard decimal form, i.e. the front
digit indicates the level. The measuring point number (and thus also the pro-
grammed reference channels) for all devices with 1, 2, 3, 5, or 10 inputs thus
always remains the same. This means, however, that, with effect from measu-
ring channel number 20, the measured value resolution in the display is limited.
If this proves to be a serious problem, it is possible, by holding down the MANU
key when switching ON, to change to continuous sequencing (and, by means of
the same key, to change back again).
Device-internal channels
A further innovation on this device is its four extra additional channels. The first
of these is programmed by default as differential measuring channel M1 - M0.
This only happens, however, if there are two sensors with the same units and
ALMEMO2390-5 15
Connecting the transducer

same decimal point position connected at measuring points M0 and M1. Howe-
ver, all four channels can be programmed with any other function channels
(e.g. U-Bat, VK, average, volume flow, etc.); (see Manual, Section 6.3.4).
As reference channels for M3 by default Mb1=M1 and Mb2=M0 are always
used; the others refer to M3 (see Section 7.7). If you want to program a volume
flow channel on M3 (measuring range ´Flow´), the flow sensor must therefore
be connected to M1 (assuming you do not want to specially program the refe-
rence channel via the interface).
Advantage If several sensors are being used for the same application, they do
not have to be reprogrammed and can be freely exchanged without losing their
function channels. If, however, the whole application operates with just one
sensor, then programming in the sensor itself makes more sense.
On the measuring instrument this gives the following channel assignment:
The three analog inputs on the ALMEMO 2390-5 are electrical-
ly isolated by means of photovoltaic relays; the maximum po-
tential difference permitted between them is 50 V DC or 60 V
AC. Sensors combined within one connector and sensors with
their own power supply, however, are electrically intercon-
nected and must therefore be operated in isolation. The volta-
ge applied to the measuring inputs themselves must not
exceed ±5 volts (between A, B, C, and D ).
The cold junction compensation for thermocouple measurement is integrated in
the device in socket M0.
00
1122
33
10 4 11 5 12 6
13 7
20 8 21 9 22 1023 11
30 1231 1332 1433 15
chann 1
chann 2
chann 3
chann 4.
M0 M0M1 M1M2 M2A2 A1
2390-5
sensors sensors
device internal
device
difference M1-M0
numbered in decimal form (default) continuous sequencing
internal
16 ALMEMO2390-5
Connecting the transducer

5. DISPLAY AND KEYPAD
5.1 Display
The display (5) on measuring instrument ALMEMO 2390-5 comprises an LCD
with 6½ x 7-segment characters, two 16-segment characters, a battery symbol,
and seven arrows to indicate the operating status.
CORR START MEM COM ALARM F
M
M MIN SEC DIM/F
Measured value display
The first thing to appear after switching ON is the measured value display with
measuring point (M) and units (DIM) as used for the channel most recently se-
lected.
Measuring point, measured value, units: 0: 23.4° C
Function display (see Section 5.2)
Measuring point, function value, function: 0: 29.7M H
Double display for temperature and humidity
If a double sensor for temperature and humidity is connected at socket M0, the
display can be switched to a double display showing both variables. To obtain
a double display, channel M10 must be selected for humidity and the PROG
key must be pressed and held down for longer than one second. With the sa-
me key combination this function can also be changed back again.
Selecting the humidity channel:
M▲
10: 34.5% H
Double display by key:
PROG
1s 23.4°C 34.5%
Even if other channels or function values are selected in standard format, the
double display will continue to apply as and when you return to channel M10.
23
BAT
ALMEMO2390-5 17
Display and keypad

Special operating states
Segment test for display This is performed automatically
each time the device
is switched ON.
Voltage supply: below 7 volts: -Symbol lights up
BAT
below 6 volts: 1:L o b A t
Sensor supply power shorter than UMIN:1:U - Lo
Checksum error during
device calibration:
Non-connected sensors,
deactivated measuring points,
deleted programming values,:
Non-permitted measuring range:
Sensor correction or scaling CORR arrow lights up
Calibration resistance switched on CORR arrow flashes
Measuring operation started START arrow lights up
Averaging in progresst arrow lights up
M
Measured value recording in progress MEM arrow lights up
Measuring point scan with output COM larrow lights up
Function selected Farrow lights up
If all functions are activated,
then Farrow flashes
Malfunctions
Malfunctions are displayed as follows and trigger an alarm; (see Manual 6.3.9):
Sensor breakage: Abbreviation flashes
1: N i C r °C
Limit value exceeded: ALARM arrow lights up
Measuring range overshot: Maximum value flashes
Measuring range undershot: Maximum value flashes
Measuring range undershot for (Cold junction)
cold junction compensation, flashes
or measuring without external
cold junction compensation,
or cold junction compensation breakage
Values range overshot (>65000): flashes
1:6 5 0 0 0
C A L E r r
1: - - - -XX
1: E r r
1: C J
18 ALMEMO2390-5
Display and keypad

5.2 Function selection and activation
Measuring instrument ALMEMO 2390-5 provides a wide variety of functions for
controlling measuring sequences, for acquiring, averaging, monitoring, and sa-
ving measured values, for outputting data to various peripheral equipment, and
for scaling, adjusting, and correcting sensors, etc.. Since these functions will
not be needed by the normal user all at once, they can be activated in various
ways on an application-specific basis.
After reinitialization (see Section 3.3) the FUNCTION key will initially have only the
following functions assigned : maximum value, minimum value, cycle, measu-
ring range, locking mode, and averaging mode, plus (with option S) the memo-
ry. Appropriate additional functions will then be activated depending on the
sensor programming (i.e. locking mode, averaging mode, etc., see below). Any
further functions that you frequently require can be enabled via the interface.
This approach is intended to maintain rapid access via the FUNCTION key and to
minimize the risk of accidentally entering incorrect information.
If it suddenly becomes necessary to have all functions activated for a limited
period, then the first time you press the FUNCTION key you must hold it down for
longer than 1 second. To verify that this has succeeded the ´F´ arrow in the dis-
play flashes.
The active functions can be selected by repeat-pressing the FUNCTION key. To
revert to the previous function arrangement press and hold down the FUNCTI-
ON key again. If a function is selected instead of a measured value, the ´F´ ar-
row in the display lights up.
Functions are shown in the display as a function value followed in the units po-
sition by a two-character abbreviation (as listed in the following table); in the ca-
se of sensor parameters, the channel number will also be shown:
Funktions Value Abbrev. Activation Memory
Maximum value (Hi) 1:127.3MH Default Device
Minimum value (Lo) 1:023.4ML Default Device
Average value 1:13.24 AV Averaging mode >0 Device
Count of averaged val. 1:1234 C Averaging mode >0 Device
Averaging mode 1:Cont AM Default Sensor
Smoothing 00 DG Hold down FUNCTION key
first time it is pressed Sensor
Diameter standardized 1: 0150.DN Measuring range ´Flow´
Cross-section area 1:0175.CS Measuring range ´Flow´Sensor
Atmospheric pressure 1013 mb Hold down FUNCTION key
first time it is pressed Device
ALMEMO2390-5 19
Display and keypad

Funktions Value Abbrev. Activation Memory
Temp. compensation 1: 023.4TC Hold down FUNCTION key
first time it is pressed Device
Memory free (option S) 01:113.2MF Default Device
Cycle 00:15:00 CY Default Device
Time of day 12:34:56 TMHold down FUNCTION key
first time it is pressed Device
Date 01.12.99 DA Hold down FUNCTION key
first time it is pressed Device
Start time (option S) 10:00:00 ST Hold down FUNCTION key
first time it is pressed Device
Start date (option S) 02.10.03 SD Hold down FUNCTION key
first time it is pressed Device
End time (option S) 17:00:00 ET Hold down FUNCTION key
first time it is pressed Device
End date (option S) 02.10.03 ED Hold down FUNCTION key
first time it is pressed Device
Baud rate, output format Un 9600 BR Hold down FUNCTION key
first time it is pressed Device
Device adress 00 AHold down FUNCTION key
first time it is pressed Device
Range 1: NiCr RDefault Sensor
Locking mode 1: 0005 LM Default Sensor
Maximum limit value (Hi) 1: 123.0LH Locking mode level <7 Sensor
Minimum limit value (Lo) 1: -010.0LL Locking mode level <7 Sensor
Analog end 1:123.4AE Locking mode level <6 Sensor
Analog start 1:000.0AS Locking mode level <6 Sensor
Base value 1:---- BA Locking mode level <5 Sensor
Factor 1:---- FA Locking mode level <5 Sensor
Exponent 1:0 EX Locking mode level <5 Sensor
Zero-point correction 1:---- ZC Locking mode level <4 Sensor
Ambient temperature 1: 250.0AT Elementflag = IR Sensor
Gain correction 1: ---- SC Locking mode level <4 Sensor
Emissivity factor 1: 0.950 EF Element flag = IR Sensor
Display mode
(Sleep/language)SLP d DM Hold down FUNCTION key
first time it is pressed Device
Activation via interface
The default functions can, if necessary, be specified via the interface (e.g. AM-
R-Control); (see Manual, Section 6.10.13.3, key F2). If you want to do without
all activated automatically functions, then you can deactivate these with the mo-
de parameter 8. (see Manual 6.10.13.2, command: f6 k8 ).
20 ALMEMO2390-5
Display and keypad