Astelco NTM-500 Product manual

New Technology Mount
Technical Reference Manual
Revision 3.8

Page 2 NTM-500 Reference Manual V-1105-3.7
“NTM” is a trademark of ASTELCO Systems GmbH
“ASTELCO” is a registered trademark of ASTELCO Systems GmbH
No part of this document may be copied or reproduced in any form without
prior written approval of ASTELCO Systems GmbH.
© 2012 ASTELCO Systems GmbH. All rights reserved.

NTM-500 Reference Manual V-1105-3.7 Page 3
Contents
Page
Introduction ................................................................................................................................ 4
Safety.......................................................................................................................................... 4
Abbreviations ............................................................................................................................. 4
1 Overview ................................................................................................................................. 7
2 General operating conditions .................................................................................................. 9
3 Installation............................................................................................................................. 10
3.1 Mechanical installation of the NTM-500 ....................................................................... 10
3.2 Installing the control unit ............................................................................................... 18
3.3 Preparing the controller cable set ................................................................................... 18
3.4 Connecting the controller cable set ................................................................................ 18
3.5 Software ......................................................................................................................... 20
4 Instrument orientation and balancing.................................................................................... 21
5 Startup, referencing and computer connection...................................................................... 24
6 Alignment to the celestial pole.............................................................................................. 31
7 Pointing model ...................................................................................................................... 33
7.1 Creating a pointing model .............................................................................................. 33
7.2 Refining a pointing model.............................................................................................. 37
8 Factory reset .......................................................................................................................... 39
Appendix .................................................................................................................................. 40
Appendix A: Parts list .......................................................................................................... 40
Appendix B: Control unit..................................................................................................... 41
Appendix C: NTM-500 connector panel and cables............................................................ 43
Appendix D: Pier interface drawing..................................................................................... 46
Appendix E: NTM-500 WebInterface.................................................................................. 47
Appendix F: Abbreviations .................................................................................................. 56
Appendix G: Cable set ......................................................................................................... 57
Appendix H: Declaration of Conformity ............................................................................. 58
Index......................................................................................................................................... 59

Page 4 NTM-500 Reference Manual V-1105-3.7
Introduction
This document is aimed to help you with the installation and the first steps with your NTM-
500. Please take some time and read it carefully before you start with the installation process.
The NTM-500 can be installed either “classically” equatorial, or as an “Alt-Alt” mount with
horizontal Right Ascension axis and used for several special purposes.
The classical equatorial mode allows long-exposure imaging without the use of an autoguider
and without the negative effects of field rotation. The Alt-Alt mode allows continuous
observation runs of regions around the zenith without any limitations of the meridian transit.
An Alt-Az setting is possible as well.
The use of state-of-the-art drive technology with this mount leads to maximum dynamic
(extremely accurate tracking and extremely rapid positioning), and also to the possibility of
very high acceleration at all slewing and tracking speeds with very short response-times and
therefore allows for the first time tracking accuracies like professional large telescopes
without periodic errors and well known problems with gear backlash and friction at various
temperatures.
Safety
Please read the safety and precaution instructions carefully before you connect the NTM-500
or power it. All safety critical issues will be marked with the following icons:
Icon Description
Damage to the device is possible.
Also: DANGER TO LIFE!
Danger of electric shock. DANGER TO LIFE!
Possible damage to the device by electro-static discharge (ESD). Take
precautions for proper grounding.
Abbreviations
Please consult the list of abbreviations used throughout this manual: Appendix F:
Abbreviations on page 56.

NTM-500 Reference Manual V-1105-3.7 Page 5
Take special care for the following items:
During operation, the NTM-500 will move fast in both axes. The mount may
make unexpected movements. Especially with long OTAs, make sure that
nobody is in the range of movement of the OTA. Make sure that there are no
obstacles in the range of movement of the OTA, no matter where the mount
points to. Always stay in safe distance from all moving parts to avoid injuries.
The motor cables carry high voltages and high currents. Never touch either
end of them when the cables are connected to the NTM-500 or to the control
unit.
Before plugging-in or unplugging the cables, the NTM-500 controller must be
disconnected from the power lines. Wait at least 3 minutes to ensure that all
internal capacitors are discharged before power is reconnected.
Before plugging-in or unplugging the cables, proper grounding must be
ensured to avoid damage to the sensitive hardware by ESD.
When unplugging the compressed air hose from the mount or the controller,
take special care as there may be some remaining air pressure inside the hose.
Install the control unit in such a way that there is at least 25cm of free space on the rear
side of the control unit and at least 10cm to the front to allow the power supply fans to
work properly.
Make sure that your observatory is properly grounded, including the spot
where you place the control unit. Missing or bad grounding can cause damages
to the electronic components of the control unit and/or the mount!

Page 6 NTM-500 Reference Manual V-1105-3.7
Lifting the NTM-500
The NTM-500 is a heavy device – it weighs about 80kg. It is highly recommended
to lift this mount only by the aid of a crane. When lifting the NTM-500, always
detach the counterweight shaft first. Please read section “3 Installation” on page
10 on how to attach and detach the counterweight shaft. Never lift the NTM-500
by the counterweight shaft!
We strongly recommend lifting the NTM-500 only as shown in Fig. 1:
Fig. 1
For lifting the NTM-500, put a rope through the hollow DEC axis and attach this rope to a
crane. The clamping set of the counterweight shaft must be taken out for this purpose. Never
attach the rope to the latitude adjustment unit and never use the latitude adjustment
unit for lifting the NTM-500!
Before turning the NTM-500 on for the first time, you must ensure that the
envelope of motion of the mount itself, the counterweight shaft with
counterweight as well as the instrument, is free of obstacles to avoid any
injuries to the users or damages to the mount or to the OTA/instrument.
Also make sure that no cables can jam up during operation of the mount.

NTM-500 Reference Manual V-1105-3.7 Page 7
1 Overview
The following drawing shows the NTM-500 mount with its parts. Please refer to the table
below for identification of the parts.
Fig. 2: NTM-500 parts identification
Part number Description
1 Base plate with pier interface and azimuth adjustment unit
2 Lock knobs for the latitude adjustment
3 Right Ascension (RA) block with connector plate
4 Telescope flange with dovetail adaptor*
5 Declination (DEC) block
6 Counterweight (example)
7 Counterweight shaft
8 Counterweight security stop and screw
9 Latitude adjustment unit
* There are two different flanges available. The standard flange has a ~100mm wide dovetail acceptance; the
optional 3" flange has a ~3" (76mm) wide dovetail acceptance.
The above parts identification will be used throughout this manual.

Page 8 NTM-500 Reference Manual V-1105-3.7
The NTM-500 is designed to operate with a wide range of user instruments, providing both
high-speed positioning and below arc-second precise tracking. The following table gives a list
of edited features at a glance:
Feature Comment
Speed * Up to 30°/s, acceleration up to 10°/s
2
Pointing By pointing model for precise pointing and tracking
Pointing accuracy < 5' without pointing model, < 5" RMS with pointing model
Tracking accuracy < 2'/h without pointing model, < 1"/h with pointing model
Load capacity
(instrument load)
Approx. 60kg (not including counterweights)
Latitude adjustment 0 – 90°
Azimuth adjustment 360° coarse adjustment, plus ±10° fine adjustment at any azimuth
position
Safety Pressure brakes that stop any movement within seconds if an error
occurs
Emergency stop Connector for emergency switch at the mount’s control panel
Network interface Fully TCI2 compliant TPL2 network interface (optional)
* Higher speed and acceleration is possible. Contact ASTELCO if your application requires
different settings.

NTM-500 Reference Manual V-1105-3.7 Page 9
2 General operating conditions
The NTM-500 and its control unit are designed for clean and non-aggressive environments
with humidity between 0% and 70% (non-condensing), and for altitudes up to 3.000m
(~10.000 ft) above sea level.
The control unit is designed for temperatures between +10°C (50°F) and +40°C (104°F), the
NTM-500 is designed for a temperature range from -20°C (-4°F) to +40°C (104°F). The
power supply for the control unit should comply with EN 50178 and UL 840 standards. It
should be fused for 2.500W.
The following table gives the typical power consumption in different operation modes:
Power rating Operation mode
5W Control computer turned off
65W Control computer running, NTM-500 turned off
85W Computer and NTM-500 turned on
135W Pressure pump running to open brakes
90 … 400W Slewing
90 … 120W Tracking
The above values represent typical operation modes. In case of non-typical operating
conditions, the power rating may increase substantially. For example, if the OTA is blocked
by an obstacle, both motors will immediately draw a lot more current and the power rating in
such a case may increase to approx. 1.400W.
When switching on the control unit, several internal condensers will be loaded, resulting in a
higher power rating just for the very first seconds of operation. Therefore, the fuse protection
should cover 2.500W in any case.
The control unit is best located in a separate room or in an environmental-safe server unit.
Direct exposure to sun light, water, humidity or temperatures below 0°C (32°F) must be
avoided under all circumstances. The provided cable set has a length of 10m to allow for
placing the control unit in an appropriate location.

Page 10 NTM-500 Reference Manual V-1105-3.7
3 Installation
Before starting the installation of the NTM-500, please make sure that you have all supplied
parts (see Appendix A: Parts list) as well as any tools needed.
In the sections of this chapter, the installation steps are described in detail. Please read these
steps first in detail, before starting the installation process. The installation should be done in
the following order:
1. Mechanical installation
2. Installing the control unit
3. Preparing the controller cable set
4. Connecting the controller cable set
3.1 Mechanical installation of the NTM-500
Before installing the NTM-500 on your pier or tripod, make sure the pier or tripod
is leveled. Next, install the NTM-500. For lifting the mount onto your socket, pier
or tripod we recommend the usage of a crane to avoid injury due to the heavy
device. The counterweight shaft must not be installed while lifting the mount!
Please see the “Lifting the NTM-500” section under “Safety” on page 4 for details! We
strongly recommend lifting the NTM-500 only as described in the “Lifting the NTM-500”
section.
Azimuth adjustment
The orientation of the NTM-500 depends on the hemisphere it is located. It should be as
shown in the following table:
Hemisphere Orientation
Northern Azimuth adjustment screws to the south
Southern Azimuth adjustment screws to the north
The figure below shows the azimuth adjustment unit. In order to perform the coarse azimuth
adjustment, open the screws indicated by the red arrows as well as the 6 screws in the top of
the base plate (1, Fig. 2). You must not take out these screws, just loosening them a bit is
enough. Once the screws are loosened, you can rotate the mount. The azimuth adjustment
unit moves along with the mount.
When the mount roughly has the correct orientation (less than ±10°), fix only the two screws
indicated by the red arrows, so that the azimuth fine adjustment unit is fixed. Make sure to
have its vertical bar in the middle of the range of the adjustment screws.

NTM-500 Reference Manual V-1105-3.7 Page 11
Fig. 3: Azimuth fine adjustment
Azimuth fine adjustment is done with the pointing model. This is described in section 6
Alignment to the celestial pole.
Please note that the coarse azimuth adjustment may have to be redone at the beginning the
pointing model, depending on the accuracy during installation. The procedure stays the same.
Once the coarse azimuth adjustment is finished, the fine azimuth adjustment allows ±10°.
When the pointing model and the adjustment to the celestial pole (and therefore also the
azimuth fine adjustment) has been completed to your satisfaction, fix the 6 screws in the top
of the base plate (1, Fig. 2). Please refer to section 6 Alignment to the celestial pole and 7
Pointing model for further details.

Page 12 NTM-500 Reference Manual V-1105-3.7
Fig. 4 a + b
Latitude adjustment
The latitude adjustment must be set to your observing latitude. The notch spacing on the
latitude adjustment unit (9, Fig. 2) is 15° starting at 0°, the fine-adjustment screw being in the
middle of its range.
Do these steps with the help of a second person!
If you need to set the observing latitude higher or lower than the setting of the current notch
allows, first open the latitude lock knobs (2, Fig. 2).
While holding the mount and telescope securely by hand, take the latitude fine
adjustment unit out of its current notch and put it into a different notch. Be careful
while doing so and make sure to hold the mount safely while the adjustment
unit is free! After having changed the latitude, fix the latitude lock knobs (2, Fig.
2) again.
Like for the fine azimuth adjustment, the fine adjustment of the latitude will be done with the
pointing model. This is described in section 6 Alignment to the celestial pole.
Counterweight shaft and provided cables
The NTM-500 comes with a set of cables routed internally through the mount body. This is
convenient as no cables move around outside of the mount during operation. For a detailed
description of these cables, and especially before connecting any of them, please see
Appendix G: Cable set on page 57.
The following procedure describes how to insert the cables into the counterweight
shaft (7, Fig. 2) while inserting the counterweight shaft into the DEC block (5, Fig.
2) of the mount. The counterweight shaft must be inserted into the mount without
any counterweights attached.
Before you start, please read the entire procedure and make sure you have fully
understood how it will work.
1. The cable set of
your NTM-500 is
already routed
through the RA
and DEC axes of
the mount, as well
as through the
clamping set (Fig.
4a) for the
counterweight
shaft.
2. The clamping set is
shipped slightly tightened, sitting in the recess at the top end of the DEC block of
the mount (Fig. 4b). Loosen each one of the screws of the clamping set with the
supplied hex wrench about two full turns.
3. Grab the cable set between the RA and the DEC block of the mount with your
fingers and pull it back carefully so that the cables now form a “loop” of about
40cm length between the RA and the DEC block as shown in Fig. 5. This will

NTM-500 Reference Manual V-1105-3.7 Page 13
allow the counterweight shaft to rotate with inserted cables when the mount is in
operation. Make sure while pulling the cables back that you simultaneously feed
the cable set from the top end of the DEC block in order not to damage the cables.
4. Verify that the flexible spiral hose around the cable set stays at the bottom end of
the cable loop, which is towards the end of the RA axis. Do not push
the spiral hose together – there must always be enough space
between the spirals so that the cable set remains flexible. The spiral
hose extends approx. 28-30cm. See Fig. 5.
Fig. 5
5. The following procedure requires some kind of
skills when the counterweight shaft will be inserted
into the DEC block while simultaneously the cables
will be inserted into the counterweight shaft’s cable
channel. A second person is absolutely required.
Proceed as follows:
a. Lever the retainer clip (Fig. 6) from the counterweight shaft’s groove, slide it a
bit upwards and turn it such that the opening of the clip aligns with the cable
channel, allowing inserting the cables.
Fig. 6

Page 14 NTM-500 Reference Manual V-1105-3.7
b. Put the counterweight shaft into the lower end of the DEC block, oriented as
shown in Fig. 7a (the cable channel looks sidewards) and insert the cables into
the channel by carefully pushing each one of the cables into the channel,
starting from the top end of the shaft towards the shaft’s lower end of the cable
channel (see Fig. 7b,c,d). After inserting the cables, slide the retainer clip back
into the groove. While you push the cables into the channel, push the
counterweight shaft carefully and slowly further upwards. Pay attention not
to damage the cables, particularly at the ends of the channel. Push the
cables into the channel until you reach the lower end of the channel and guide
the cables out of the shaft. Still hold the counterweight shaft with one hand so
that it will not slide out of the DEC block.
c. If you have opened the clamping set far enough in
step 2 above, you can slide the counterweight shaft
all the way up until it stops at the internal hard stop
of the DEC block and cannot be pushed further
upwards. Verify that the counterweight shaft
has been pushed far enough up so that the top
end of the shaft aligns with the top end of the
clamping set (see Fig. 8). This is of essential
importance for the clamping effect of the
clamping set and for the secure mounting of the
counterweight shaft with installed counterweights!
d. Still holding the counterweight shaft in place, turn
it such that the cable channel now faces exactly
downwards.
e. Put the supplied spacer (Fig. 9) into the cable
channel such that it closes the channel at its top
end where the clamping set is located (see Fig.
10). The spacer should not extend above the
clamping set. Hold the spacer in place with a
Fig. 7 a, b, c, d
Fig. 9
Fig. 8
Fig. 10

NTM-500 Reference Manual V-1105-3.7 Page 15
finger so that it does not slip into the shaft until you have tightened the
clamping set in the following step. You can use a small piece of tape to hold
the spacer in place so you have both hands free for the next step.
f. Push the counterweight shaft from the bottom upwards against the hard stop
with one hand and while doing so, tighten the screws of the clamping set using
again the supplied 5mm hex wrench, see Fig. 11).
Fig. 11
In a first round, tighten all screws. Verify in a second round that every single
screw is tightened securely. This will tighten the counterweight shaft and
prevents it from falling out of the DEC block. By trying to pull the
counterweight shaft downwards (out of the DEC block), verify that the
clamping set has been tightened enough.
g. At this point, you need to adjust the cable length of the cable loop such that the
spiral hose around the cable set leads into the round end of the cable channel.
Carefully pull the cable set from the top end of the DEC block while
simultaneously carefully pushing the cable set into the cable channel of the
shaft until the spiral hose reaches approx. 3-4cm deep into the cable channel.
About one turn of the spiral hose should extend into the long cable channel
(not only into the round opening), as shown in Fig. 12:

Page 16 NTM-500 Reference Manual V-1105-3.7
Fig. 12
h. Verify that the spiral hose is wrapped around the cable set on the entire length
from the RA block to the DEC block and that it is “stretched” (not
compressed), as shown in Fig. 12 above. If this is not the case, the mount
must not be operated! Repeat the appropriate steps of this procedure!
6. The NTM’s telescope flange (4, Fig. 2) has a
dedicated cable groove to accept and guide
the cables out of the flange (see Fig. 13).
Screw off the holding bridge (Fig. 14) on one
side only with a Phillips head screwdriver
from the channel, route the cables coming out
of the clamping set into the groove and put
the holding bridge in place again, securing it
with the previously removed screws. Make
sure that no parts of the cables extend above
the cable groove as this would later interfere
with the dovetail bracket of your
OTA/instrument when you place the
OTA/instrument onto the mount. Refer to Fig.
15. In case you removed the bridge completely,
make sure the holding bridge is inserted back
such that the countersinks (red arrows, Fig. 14)
are on the top side of the bridge, so the screws
will be mounted flush with the flange’s surface.
Fig. 13
Fig. 14

NTM-500 Reference Manual V-1105-3.7 Page 17
Fig. 15 a, b, c
7. The cables now need to be routed away from the mount, along your OTA or
instrument. It is very important that the cables are being tightened
to the OTA/instrument in such a way that they cannot interfere
with any parts of the NTM when the mount is moving. Especially,
the cables must not hang down!
8. For now, leave the counterweight shaft without counterweights; these will be
installed in a later step.
Warning
Never put your finger into the rear opening
of the mount (for the counter weight shaft)
when the mount is in operation! A sudden
closing of the brake can squeeze parts of the
finger considerably!

Page 18 NTM-500 Reference Manual V-1105-3.7
3.2 Installing the control unit
Make sure that power is disconnected from the control unit.
The control unit, containing the control computer, must be installed with some distance to
adjacent walls, to ensure proper work of the cooling fans. To the front there should be at least
10 cm, to the back at least 25 cm distance. Also refer to section 2 General operating
conditions. Do not yet power on the control unit!
Fig. 16
3.3 Preparing the controller cable set
Connect the emergency button cable to the NTM-500 and install the button in a convenient
place, where you have good and easy access to it in an emergency case. Pressing the
emergency button will halt the system and activate the NTM-500’s brakes.
Pass the NTM cable set between the mount and the protected place, where the control unit
will be installed. The cable must not be bent too much to avoid damage. The minimum radius
for bending the cable is 10cm. Do not connect the cables yet.
3.4 Connecting the controller cable set
Please make sure that the control unit was disconnected at least 3
minutes from the power before you start to plug-in or unplug the cable
set from or to the control unit respectively from or to the mount.
Whenever connecting or disconnecting any cables, make sure that
the control unit is switched “OFF” and at least 3 minutes have
passed!
Do not touch any of the pins of the connectors, since ESD can lead to
damage of sensitive parts (e.g. the position encoders).
Always connect the NTM-500 first, then the control unit. All cables are pin-coded. A wrong
connection of the cable set is impossible.
Always disconnect the control unit first, then the NTM-500.
Now connect the cable set to the NTM-500’s rear connector panel first:

NTM-500 Reference Manual V-1105-3.7 Page 19
Fig. 17
Connect the MOTORs, aligning the arrows on the side of both connectors (see Fig. 17)
– be careful – the connectors need to be aligned precisely so that the pin on the inside
of the connector (see Fig. 18) matches its counterpart! If not aligned precisely, the
connector will be damaged!
Connect the ENCODERS, making sure all pins align correctly
Connect the AIR
Connect the EMERGENCY STOP (make sure not to use the LAN socket!)
Once done, connect the other end of the cable set to the control unit:
Connect the MOTORs, aligning the arrows on the side of both connectors
Connect the ENCODERS, again making sure all pins align correctly
Connect the AIR
Fig. 18
Now connect the GPS receiver to either one of the two available sockets (round or
rectangular plug, depending on the model supplied, located between the “DOME” and the
“ENCODERS” jacks), and put it in a place where it has a good and free view to the sky. A
good GPS signal is mandatory to achieve high accuracy with your mount. Now also connect
the LAN cable from your PC network to the LAN socket of the control unit’s front panel
(not to the mount!).
The sockets for connecting a monitor as well as for keyboard and mouse are for
factory use only.

Page 20 NTM-500 Reference Manual V-1105-3.7
Disconnecting the AIR hose from the control unit
As the system is under pressure in normal operation, special care has to be taken
when disconnecting the AIR plug from the control unit. Always grab the AIR
hose with one hand and hold it tightly, before you disconnect the hose with the
other hand by pushing the connector lock towards the control unit!
Powering the control unit
When power is connected to the control unit and the switch on the rear side of the unit is
turned on, you can press the “POWER” button on the front side of the connector panel.
After pressing the “POWER” button, the green POWER-LED and the red ERROR-LED will
start flashing alternately for a few seconds. This indicates the early startup phase of the
control unit.
Next, the control computer inside the control unit starts up. This is indicated by the flashing of
the red ERROR-LED. This can take up to 60 seconds. If the red ERROR-LED does not stop
flashing after several minutes, unpower the control unit and check all the cable connections
again and then re-power the control unit.
Once all the LEDs are off, the system is ready and running.
Unpowering the control unit
The control unit can be unpowered at any moment. No special care must be taken for shutting
down the computer running inside the unit. The unpowering is done by pressing the
“POWER”-button on the front side of the control unit again.
During the shut-down process, the control unit may give some “beep” signals.
3.5 Software
To do the procedure described in the following section 4 Instrument orientation and
balancing, no software control is required. For a detailed description of the control software –
the web interface and AsTelOS Express – please refer to section 5 Startup, referencing and
computer connection and to Appendix E: NTM-500 WebInterface.
The NTM-500 optionally features a fully TCI2 compliant TPL2 based network interface. All
functionality from switching the system on to pointing model creation is accessible via
network. Please read the TCI2 documentation for further details.
A detailed description of the optional NTM-500 TPL2 control software is provided in the
optional TPL2 Software Documentation.