Vermes MHC 48-1 User manual

VTK-VS-BA-058e-B | User Manual MHC 48-1 | Introduction
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VTK-VS-BA-058e-B | User Manual MHC 48-1 |Introduction
Content
1Introduction ................................................................................... 3
1.1 Intended Use............................................................................................................... 4
1.2 Abbreviations .............................................................................................................. 4
2Main Function: Heating................................................................... 5
3Quick Start ..................................................................................... 6
4Heater Control Unit MHC 48-1 ...................................................... 10
4.1Technical Data........................................................................................................... 10
4.2 Front Side .................................................................................................................. 11
4.3 Top Side..................................................................................................................... 12
4.4 Function Keys ............................................................................................................ 13
4.5 Beeper alarm............................................................................................................. 15
4.6 Setting up the MHC 48-1........................................................................................... 16
4.7 Menu Structure......................................................................................................... 20
4.7.1 Top Menu (Basic Level) ............................................................................................. 20
4.7.2Second Menu Level ................................................................................................... 22
5Communication Interfaces ............................................................ 24
5.1 Serial Interface RS-232C: 9-Pin Sub-D ....................................................................... 24
5.2 Commands ................................................................................................................ 25
5.2.1 Command Overview.................................................................................................. 26
5.2.2 Command Explanations ............................................................................................ 27
5.3 PLC Interface: 15-pin, Sub-D ..................................................................................... 34
6Error Messages ............................................................................. 35
6.1 Table of Error Messages............................................................................................ 35
6.2 Explanations of Error Messages ................................................................................ 37
7Safety Notes ................................................................................. 44
7.1 Obligations and Liability............................................................................................ 44
7.2 Residual Risks ............................................................................................................ 44
7.3 Specification and Technical Notes ............................................................................ 45
7.4 Warnings ................................................................................................................... 45
7.5 Protective Equipment and Safety Clothing ............................................................... 45
8Attachments................................................................................. 46
8.1 Dimensional Drawing MHC 48-1 ............................................................................... 46
8.2 Connection of MHC 48-1 with Adapter Cable MHC-48 for Power Supply,
extendable ................................................................................................................ 47
8.3 Connection Diagram PLC Interface ........................................................................... 53
8.4 Overview of the Function Keys of the MHC 48-1 ...................................................... 54
8.5 Temperature Correction ........................................................................................... 57
8.5.1 Basics of the Temperature Correction ...................................................................... 57
8.5.2 Finding the Correction Parameters m and T ............................................................. 59
8.5.3 Entering the Correction Parameters m and T ........................................................... 60
8.6 Firmware Update with the MHC_ Firmware_Loader................................................ 61
8.7 EC Declaration of Conformity.................................................................................... 65
9Index ............................................................................................ 66

VTK-VS-BA-058e-B | User Manual MHC 48-1 | Introduction
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1INTRODUCTION
This User Manual explains the main properties and functions of the heater controller MHC
48-1 (see Picture 1). You can use it to control integrated heaters (for a list of compatible
heaters, see chapter 1.1)connected with a microdispensing system.
The pictures in this manual might differ slightly from the final product.
In the case of further questions, consult our Technical Support.
Technical Support VERMES Microdispensing GmbH
Rudolf-Diesel-Ring 2
83607 Holzkirchen
Tel.: [phone]
Fax.: [phone]
[e-mail]
www.vermes.com
Service hours Monday - Friday 9.00 to 17.00 (CET).
Picture 1: MHC 48-1 (with Adapter Cable MHC-48 for Power Supply, PLC & RS232)

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VTK-VS-BA-058e-B | User Manual MHC 48-1 |Introduction
1.1 Intended Use
You can use the MHC 48-1 for the following applications:
•Controlling the nozzle heater of your VERMES Microdispensing System
•Keeping a dispensing application stable at a constant temperature
The MHC 48-1 can control heaters working on an extra-low voltage basis (48 V). See the de-
vices listed below.
Heater:
MDFH-48-CC (Order no. 1013967, power consumption 20 W, maximum 180 °C)
MDFH-48-CC right (Order no. 1014014, power consumption 20 W, maximum 180 °C)
MDFH-48-CC left (Order no. 1014145, power consumption 20 W, maximum 180 °C)
MDFH-48-CC-HC (Order no. 1014147, power consumption 20 W, maximum 180 °C)
MDFH-48-CCI (Order no. 1013969, power consumption 20 W, maximum 180 °C)
MDFH-48-CH-TA (Order no. 1014052, power consumption 20 W, maximum 180 °C)
MDFH-48-CH-TA right (Order no. 1014059, power consumption 20 W, maximum 180 °C)
MDFH-48-CH-TA-B (Order no. 1014353, power consumption 20 W, maximum 180 °C)
MDFH-48-CH-TA-B +10 mm (Order no. 1015272, power consumption 20 W, maximum
180 °C)
MDFH-48-CHI-BY (Order no. 1014233, power consumption 20 W, maximum 180 °C)
MDH-48-BY-45W (Order no. 1014533, power consumption 45 W, maximum 180 °C)
1.2 Abbreviations
Abbr.
Full name
BL Boot loader
FW Firmware
MDC Controller (MicroDispensingControl unit)
MDF Fluid box (MicroDispensingFluid box)
MDS MicroDispensingSystem
MDV Valve (MicroDispensingValve)
MHC Microdispensing heater controller
MV Mean value
PWM Pulse-width modulation
SSD Seven-segment display

VTK-VS-BA-058e-B | User Manual MHC 48-1 | Main Function: Heating
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2MAIN FUNCTION: HEATING
The MHC 48-1 has the following main function: controlling heaters. This chapter describes
this main function.
VERMES MicroDispensing Systems can be fitted with a heater. With a heater, you can con-
trol the dynamic viscosity of the fluid you want to dispense. For some fluids, dispensing
without heating is impossible. Heating may also be required to ensure a constant process
temperature or is necessary when the dispensing has to take place above room tempera-
ture.
There are two main types of heater: nozzle heaters and cartridge heaters. With the MHC 48-
1, you can control nozzle heaters. For a list of heaters compatible with the MHC 48-1, check
chapter 1.1.
Picture 2 shows one example, the MDFH 48-CC, connected with a MicroDispensing Valve.
The heater contains a heating element, to create the necessary warmth near the nozzle (see
Picture 3, red part). To check the temperature, the heater also contains a Pt100 sensor (see
Picture 3, blue part). This allows the MHC 48-1 to keep the target temperature near the noz-
zle.
Since there is a small but necessary distance between the sensor and the nozzle, in some
applications might be a slight difference between the temperature measured at the Pt100
sensor and the actual temperature at the nozzle. For those applications, you have the possi-
bility to use a temperature correction. You can change the correction parameters with the
serial command “CON:TCORR” (see chapter 5.2.2).
We recommend you use the temperature correction only after you have fully understood
the system. You can find more information in the attachment 8.3.
Picture 2: MDV with MDFH 48-CC
Picture 3: MDFH 48-CC schematic with heating element (red) and Pt100 sensor (blue)

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VTK-VS-BA-058e-B | User Manual MHC 48-1 |Quick Start
3QUICK START
This chapter provides the necessary information to start your MHC 48-1 and to use its basic
functions (switching on the heater, setting the target temperature). We recommend to read
the whole manual before you start working with the MHC 48-1, but this chapter gives you a
quick introduction to use the basic functions. Once you want to use other features of the
MHC 48-1 (e.g. the serial interface), you will need to refer to the corresponding chapters.
With the following steps, you can connect your MHC 48-1 and use the basic functions.
Step 1: Plug in adapter cable
You need your Adapter Cable MHC-48. You either have the Adapter Cable MHC-48 for
Power Supply, PLC & RS232 (see Picture 4) or an Adapter Cable MHC-48 for Power Supply,
extendable (see Picture 5). For the quick start and the use of the basic functions, it makes no
difference which one you use. This chapter uses the Adapter Cable MHC-48 for Power Sup-
ply, extendable.
Plug the adapter cable in the sub-D socket on top of your MHC 48-1 (see Picture 6). Screw
the sub-D depth bolts tight.
Picture 4: Adapter Cable MHC-48 for Power Supply, PLC & RS232
Picture 5: Adapter Cable MHC-48 for Power Supply, extendable

VTK-VS-BA-058e-B | User Manual MHC 48-1 | Quick Start
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Step 2: Connect power supply
Connect the 4-pin PCB connector of the adapter cable with the counter part of your power
supply (see Picture 7 and Picture 8). You power supply must be set to 48 V DC.
Picture 6: Connect the adapter cable
Picture 7: Power connection (not yet connected)
Picture 8: Power connection (connected)

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VTK-VS-BA-058e-B | User Manual MHC 48-1 |Quick Start
Step 3: Connect heater
You have to connect the heater cable of your heater (e.g. MDFH 48-CC, see Picture 19 with
MDFH isolation body NAN-fix included) with the socket for heater on top of the MHC 48-1 (see
Picture 9). Push the plug in; then screw the connection tight. Press the case slightly forward
while screwing.
Step 4: Switch ON the MHC 48-1
The MHC 48-1 has no separate ON/OFF button. Turn it ON by turning the power supply
(48 V DC) ON.
After the start the display will show “OF” (= off), since the heater is OFF. Later you can
change the settings of your MHC 48-1, so that the heater is ON after the start-up of the
MHC 48-1 and the display shows the current temperature (see chapter 4.7).
Step 5: Set target temperature
Press the Set key shortly to change the display for the target temperature. When showing
the target temperature, the display is flashing rapidly. By pressing the Up-key or Down-key
(see Picture 10 and Picture 11)you can change the target temperature. With the Up-key, you
increase the temperature; with the Down-key, you decrease the temperature. The highest
temperature you can set is 99 °C. For temperatures over 70 °C, you will get a warning sound.
After approx. 3 s without pressing a key, the display jumps back to the current temperature.
You can also press the Set-key (see Picture 12)shortly, to jump back directly.
Picture 9: Heater connected
Picture 10: Up-key
Picture 11: Down-key

VTK-VS-BA-058e-B | User Manual MHC 48-1 | Quick Start
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Step 6: Switch ON the heater
You activate the heater by pressing the Set-key (see Picture 12)longer. The display changes
to the current temperature, which is given in °C. The value shown is flashing slowly. This is
the case, until the current temperature has reached the target temperature and is stable.
Then the display of the current temperature is steady without flashing.
When the heater is ON, you can still change the target temperature as shown in step 5. The
display of the current temperature will again flash slowly, until the current temperature has
reached the target temperature. To deactivate the heater, you press the Set-key longer. The
display will show “OF”.
CAUTION! (High temperatures)
The MHC 48-1 can control integrated nozzle heaters at temperatures of up to 99 °C. Do not
touch the nozzle area during operation. Afterwards only touch it once it has cooled down.
Step 7: Save target temperature
If you change a target temperature in the main menu, this is not saved after a re-start. To
save a new target temperature for future use, follow the instructions below.
Press the key combination Up-key + Down-key together for a long moment. The display
jumps to the menu item “H.1” in the second menu level (see chapter 4.7.2). Press the Set-
key shortly. You see the currently saved target temperature. With the Up-key and the
Down-key, you can set the desired target temperature. A short pressing increases the value
by 1 (Up-key) or decreases it by 1 (Down-key). By pressing the key longer, the display starts
to scroll up or down, respectively.
With another short pressing of the Set-key, you save your changes. The display jumps back
to the menu item “H.1”. If you want to abort your changes without saving, you have to press
the Set-key longer to jump back to “H.1”.
With pressing the Set-key longer in the menu item “H.1”, you jump back to the top menu
level to the display of the current temperature. Be aware that this change of the saved tar-
get temperature only works after a re-start. Alternatively, you can set the target tempera-
ture manually to the new value (see step 5).
You can find a detailed description of MHC 48-1 in chapter 4. The interfaces and serial com-
mands are explained in chapter 5 and potential error messages in chapter 6.
Picture 12: Set-key

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VTK-VS-BA-058e-B | User Manual MHC 48-1 |Heater Control Unit MHC 48-1
4HEATER CONTROL UNIT MHC 48-1
This chapter describes the menu structure, keypad and the functions of the heater control
unit MHC 48-1. It also explains how to set it up.
IMPORTANT NOTE! (No ON/OFF button)
The MHC 48-1 has no separate ON/OFF button. Just connecting the power supply (48 V DC)
will turn it ON and disconnecting it will turn it OFF.
4.1 Technical Data
Parameter Value
Dimensions 135 mm H x 42 mm W x 75 mm D (with adapter)
(see also dimensional drawing, page 46)
Weight ca. 200 g (+ 130 g for the adaptor)
Supply Voltage 48 V DC
Power Consumption 25 W
Current Consumption 550 mA max.
During start-up, this value can increase by a fac-
tor of 5 (start-up peak).
Operating Temperature 0 °C to 50 °C
Air Humidity 35 % till 80 % rH
Casing Type Case with clamp for top hat rail
Color of Casing Silver and blue
Display Seven-segment display (SSD)
Display Color Green letters on dark background
Keypad 3 function keys
Color of Keys Blue-white, orange
Plug Contacts (Top)Socket for Cable for Heater
9-pin Sub-D socket for Adapter Cable MHC-48 for
Power Supply, PLC & RS232
(At the adapter cable:
Power Supply: 4-pin PCB connector for power
connection (48 V DC)
PLC: 15-pin Sub-D socket
RS-232C: 9-pin Sub-D socket)

VTK-VS-BA-058e-B | User Manual MHC 48-1 | Heater Control Unit MHC 48-1
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4.2 Front Side
Display:
The display is a seven-segment display with two digits and shows data and menu options.
Display Explanation
-- No heater connected
OF Heater connected, but deactivated
Current temperature Heater connected and activated
Until the current temperature has reached the target temperature, the
display flashes slowly. When the display shows the target temperature,
it flashes
quickly
(see also chapters 4.4 and 4.7.1).
Keypad with three softkeys:
You select menu options to control the system, change parameters or display values with
these three keys (see also chapters 4.4 and 4.7). When you press a key, the keypad signal
sounds (see chapter 4.5).
You can lock the keypad with the serial command “SYS:KLOCK1”. You can unlock the keypad
with the serial command “SYS:KLOCK0” or by switching OFF the MHC 48-1 and then back
ON.
Display
Keypad
(3 softkeys)
Picture 13: Front side of the MHC 48-1

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VTK-VS-BA-058e-B | User Manual MHC 48-1 |Heater Control Unit MHC 48-1
4.3 Top Side
M12 Socket for Cable for Heater:
A socket for the connection with a heater cable.
Adapter Cable MHC-48 for Power Supply, PLC & RS232:
The Adapter Cable MHC-48 for Power Supply, PLC & RS232 connects the heater controller to
a power supply. Additionally is has a RS-232C interface and a PLC interface. You have to or-
der the adapter cable separately (order no. 1014146). Alternatively you can use the Adapter
Cable MHC-48 for Power Supply, extendable (order no. 1014187; see attachment 8.2).
RS-232C interface (9-pin):
Since the system offers the possibility of external programming and firmware updates via
PC, a local RS-232C is integrated to receive the data. For a description and the communica-
tion protocol, refer to page 24; for an explanation of the serial commands, refer to page 25.
PLC interface (15-pin):
With help of the PLC interface, you can switch the heater externally ON or OFF. You can find
a description and the pin functions in chapter 5.3.
Power connection:
Connects the control unit to a power supply. It needs 48 V DC. Base power consumption of
the MHC 48-1 is 5 W. For heaters, check chapter 1.1.
RS-232C interface (9-pin)
4-pin PCB connector
for power connection
PLC interface
(15-pin)
Picture 14: Top side of the MHC 48-1
Socket for heater cable
Adapter Cable MHC-48
for Power Supply, PLC
& RS232

VTK-VS-BA-058e-B | User Manual MHC 48-1 | Heater Control Unit MHC 48-1
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4.4 Function Keys
All function keys have a keypad alarm. Pressing one of the keys creates a short beeping
noise, so you can hear if a key was pressed correctly. If you press a key in a menu, where it
has no function, a different alarm beep sounds. This can happen for example if you try to
switch ON the heater, but the connected device is incompatible. You can turn the keypad
alarm OFF in the menu item A.L “Setting the beeper alarm”(see chapter 4.7.2).
IMPORTANT NOTE! (Pressing a key long or shortly)
It makes a difference, if you press a function key only shortly or longer. You activate differ-
ent functions.
IMPORTANT NOTE! (Key lock)
With the serial command “SYS:KLOCK1” from your computer you can lock the keypad of the
MHC 48-1. If the lock is ON, pressing a key only results in the message “lo” (=”locked”) on
the display. To deactivate the key lock, you have to send the command “SYS:KLOCK0” or to
re-start the MHC 48-1. The key lock function helps to prevent unauthorized changes of sys-
tem parameters or settings.
Function Key Function
Up key
By shortly pressing the Up key, you increase a numerical value by 1, where ap-
plicable, or you jump to the next value, when there is a distinct selection.
... or ...
When you are in the menu item of the actual temperature (or the menu item
“OF” with heater turned OFF), shortly pressing the Up key once brings you di-
rectly to the setting of the target temperature. By pressing again shortly, you
can increase the value of the target temperature by 1.
... or ...
By shortly pressing the Up key in the second menu level, you switch to the
next menu item.
In a menu item with numerical values, you can press the Up key longer and
the display runs quickly upwards through the numbers. This allows you to
make a big change quicker. In menu items, where you select between a num-
ber of options, it works similarly, e.g. when setting the baud rate.
In the second menu level, pressing the Up key longer has no function.
Down key
By shortly pressing the Down key, you decrease a numerical value by 1, where
applicable, or you jump to the preceding value, when there is a distinct selec-
tion.
... or ...
When you are in the menu item of the actual temperature (or the menu item
“OF” with heater turned OFF), shortly pressing the Down key once brings you
directly to the setting of the target temperature. By pressing again shortly,
you can decrease the value of the target temperature by 1.
... or ...
By shortly pressing the Down key in the second menu level, you switch to the
preceding menu item.
In a menu item with numerical values, you can press the Down key longer and
the display runs quickly downwards through the numbers. This allows you to

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VTK-VS-BA-058e-B | User Manual MHC 48-1 |Heater Control Unit MHC 48-1
make a big change quicker. In menu items where you select between a num-
ber of options it works similarly, e.g. when setting the baud rate.
In the second menu level, pressing the Down key longer has no function.
Up key + Down key (together)
When you are in the basic menu level and press the Up key and Down key to-
gether longer, the display jumps to the menu item “H.1” in the second menu
level.
When you are in the second menu level and longer press the Up key and
Down key together, the display jumps back to the basic menu level.
In any menu item where you can change values (both numerical values like the
target temperature or selecting from a range of options like with the baud
rate), the display jumps to the maximum value by shortly pressing the Up key
and Down key together. By pressing Up key and Down again shortly together,
the display jumps to the minimum value of this parameter. With any further
short pressing of both keys together, the display switches between maximum
and minimum.
Set key
In the basic menu level, by pressing the Set key longer, you switch the heater
ON or OFF.
In the basic menu level, by pressing the Set key shortly, you switch between
the display of the target temperature and the display of the actual tempera-
ture (or the display “OF”, if the heater is turned OFF).
In the second menu level, when you press the Set key longer, the display
jumps back to the basic menu level.
In the second menu level, when you press the Set key shortly, the display
jumps into a submenu where you can change the setting for the parameter of
the menu item from which you started.
Once you have changed the values in one of the submenus, you can save
these values by shortly pressing the Set key. Afterwards the display jumps
back to the menu item from where you came.
Once you have changed the values in one of the submenus, you can abort
these changes by pressing the Set key longer. Afterwards the display jumps
back to the menu item from where you came.
In case of an error, you can confirm the error message by shortly pressing the
Set key.

VTK-VS-BA-058e-B | User Manual MHC 48-1 | Heater Control Unit MHC 48-1
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4.5 Beeper alarm
The MHC 48-1 has an acoustic warning system. The acoustic warning system is the beeper
alarm. The alarm beep sounds in four situations:
•After start-up to announce the system is ready (longer beep)
•When an error appears (continuous series of short beeps until you have confirmed
the error)
•When a heater is connected or disconnected (short beep)
•When during heating the actual temperature has reached the target temperature
(longer beep)
•When the target temperature is set to 70 °C or more (longer beep, once the dis-
play jumps back)
You can switch OFF the beeper alarm in the menu item “A.L” (see chapter 4.7.2). Press the
Set-key shortly and then select the desired setting. You have the following choices:
•Turn all sound OFF (0)
•Only keypad alarm ON (1)
•Only beeper alarm ON (2)
•Both keypad alarm and beeper alarm ON (3)
In a new system the beeper alarm is set to ON.
You have to distinguish the beeper alarm from the keypad alarm, which is explained in chap-
ter 4.4. You can turn them ON and OFF independently.

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VTK-VS-BA-058e-B | User Manual MHC 48-1 |Heater Control Unit MHC 48-1
4.6 Setting up the MHC 48-1
This chapter describes how to set up your MHC 48-1 and how to connect it with your
VERMES Microdispensing System (see Picture 15). You can find an alternative setup with the
use of the Adapter Cable MHC-48 for Power Supply, extendable instead of Adapter Cable
MHC-48 for Power Supply, PLC & RS232 in attachment 8.2.
When mounting the MHC 48-1, leave sufficient space around the unit to avoid overheating
and allow the required ventilation. You should ensure a minimum distance between the
control unit and any other object (at least 1.5 cm). Heat should not be accumulated nor ex-
ternally be introduced. If you use several MHC 48-1 in a row, the minimum distance should
be 2.5 cm between them. Do not obstruct natural convection. Ventilation from the bottom
side and air exhaust above is important.
You can mount the MHC 48-1 with the clamp for a top head rail at the bottom (see Picture 16)or
with the hook-and-loop fastener at the side. Additionally there are two bore holes in the back side
for another top hat rail (see Picture 17). The clamp for this top hat rail and two screws are part of
the package. Please make sure not to screw in deeper than 5 mm.
Picture 15: MHC 48-1
Picture 16: Bottom side of the MHC 48-1 with the clamp for a top hat rail

VTK-VS-BA-058e-B | User Manual MHC 48-1 | Heater Control Unit MHC 48-1
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Adapter Cable MHC-48 for Power Supply, PLC and RS232
Push the Adapter Cable MHC-48 for Power Supply, PLC & RS232 into the sub-D socket on top of the
MHC 48-1 (see Picture 18). Screw it tight with the two UNC 4-40 screws. This adapter cable enables
the power supply for the MHC 48-1 and offers a PLC socket and a serial RS-232C socket.
Heater connection
You have to connect the heater cable of your heater (e.g. MDFH 48-CC,see Picture 19 with
MDFH isolation body NAN-fix included) with the socket for heater on top of the MHC 48-1 (see
Picture 20). Push the plug in; then screw the connection tight. You should press the case slightly
forward while screwing.
Picture 18: Power supply connected (48 V DC)
Picture 19: MDFH 48-CC (with MDFH isolation body NAN-fix)
Picture 17: Back side of the MHC 48-1 with the bore holes

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VTK-VS-BA-058e-B | User Manual MHC 48-1 |Heater Control Unit MHC 48-1
Picture 21 shows the integrated heater from above (the side connected with the valve body). In
Picture 22, you can see the heater without the MDFH isolation body NAN-fix.
CAUTION! (High temperatures)
The MHC 48-1 can control integrated nozzle heaters at temperatures of up to 99 °C. Do not
touch the nozzle area during operation. Afterwards only touch it once it has cooled down.
Picture 20: Heater connected
Picture 21: MDFH 48-CC with Isolation Body NAN-fix from above
Picture 22: MDFH 48-CC

VTK-VS-BA-058e-B | User Manual MHC 48-1 | Heater Control Unit MHC 48-1
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RS-232C Connection
You can control your MHC 48-1 from your PC via the serial RS-232C interface. This offers several
functions you cannot access via the keypad. Push the PS-232C plug into the 9-pin Sub-D socket on
the Adapter Cable MHC-48 for Power Supply, PLC & RS232 (see Picture 23).
Power connection of the MHC 48-1
The MHC 48-1 needs an external power supply of 48 V DC. You have to connect this to the 4-pin
PCB connector (see Picture 24). The connection has to go to pin 2 and pin 3.
Picture 23: MHC 48-1 with RS-232C connection
Picture 24: Power supply connected (48 V DC)

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VTK-VS-BA-058e-B | User Manual MHC 48-1 |Heater Control Unit MHC 48-1
4.7 Menu Structure
The menu of the heater control unit MHC 48-1 contains two menu levels. The top level is the
basic level. The basic level offers you temperature information and the basic settings of your
heater (ON/OFF, target temperature). In the second menu level, you have the menu items
where you can change parameters or settings (e.g. saving target temperature, parameters
of the serial interface or the beeper alarm, system reset).
The function of a key depends on the menu, you are in and if you the press the only a short
moment or longer. The details will be explained for each menu level. The table in attach-
ment 8.3 gives an overview of all the different key functions, depending on menu level.
If you are not in the top level of the menu, the display jumps back after approx. 20 s without
pressing a key to the current temperature.
4.7.1 Top Menu (Basic Level)
The top level of the menu is the basic level. In the basic level, you find the temperature dis-
play and the basic settings of your heater (e.g. ON/OFF, setting the target temperature).
This is an overview of the top menu of the MHC 48-1:
Picture 25: Top menu level (Basic Menu Level)