sat-nms ACU-19 User Manual

5.6 Setup

The page 'Setup' contains the ACU's installation parameters. The page displays a table with the parameters actually set. Each parameter value is a hyper-link to a separate page which lets you change this parameter. This parameter change page shows the actual parameter setting either in an entry field or in a drop down box. You may change the parameter to the desired value and then click to the 'Submit' button to pass the changed value to the ACU ODM. The ACU automatically returns to the setup page when the parameter has been changed. To cancel a parameter modification you already started, either use the 'Back' button of you web browser or click to the 'Setup' button on navigation bar. Both returns to the setup page without changing the parameter you edited.

The table below lists the settings provided by this page.

General

This section of the setup page contains some general setup parameters.

Parameter Name	Description
Axes control mode	The ACU knows two axes control modes. The PARALLEL mode treats the azimuth/elevation axes independently. If a new pointing is commanded, both motors are activated in parallel, the antenna moves to the new location in the shortest possible time. In SEQUENTIAL mode, the ACU does not move the elevation axis while the azimuth motor is running. The antenna movement is done sequentially: First azimuth, then elevation. You should prefer the PARALLEL mode unless special conditions require a sequential antenna movement. The performance of the ACU in terms of pointing speed and wind load compensation will be much better in PARALLEL mode.
Date / time	By changing this value you can set the internal clock of the ACU. The clock is set as soon you click to the 'Submit' button in the data entry dialog. The most precise method to set the time is to enter a time one or two minutes ahead and click to 'Submit' when this time is reached.
RS485 address	With this parameter you select the device address used control the ACU through a serial interface. See chapter 7.3 The RS232 remote control interface for more information about this. At ACU-RMU and ACU19 this parameter has to be set to 'NONE'. If you use a *sat-nms* Handheld this parameter has to be set to 'TERM'. The Handheld function is not implemented in ACU-RMU and ACU19 Version.
Watchdog pulse on AUX8	The AUX 8 output may be configured to act as a heartbeat output. If enabled, the output switches every 1000 ms between on/off. If using this signal for an external watchdog circuit, be aware that in adaptive tracking mode delays of some seconds are possible while the acu calculates the orbital model.
Display refresh	With this parameter you select the refresh-rate of the ACU's main window. This parameter is available from software version 2.1.007 or higher.
Note	The ACU's pointing page by default shows the title 'Antenna pointing'. By entering a different text here, you can make the ACU show a customized title.

Azimuth / Elevation / Polarization

The Azimuth / Elevation / Polarization sections contains the parameters which are specific to the individual axis. They are the same for each axis.

Parameter Name --- Description
Antenna diameter --- Set this parameter to the dish diameter. Units with the tracking function installed use this value to estimate some tracking parameters. With offset antennas, the diameter settings are different for the azimuth / elevation axes. This lets the ACU calculate suitable tracking step sizes individually for each axis.
Step delta --- This parameter defines size of a step the antenna moves when you click to the arrow buttons on the ACU main page. If you are using the arrow buttons to fine-tune the antenna pointing manually, the best value is the pointing hysteresis described below. This lets you move the antenna the smallest possible step when you click to an arrow button. For special applications however it might be helpful to set the step delta to a much greater value.
Position sensor type --- With this parameter you set the type of position sensor the ACU shall read for this axis. Principally, the ACU is capable to read SSI, RESOLVER and ANALOG type position sensors. The selected sensor type must match the type of interface board installed in your ACU. It is not possible to switch from SSI to RESOLVER or vice versa without changing the interface module.When selecting a SSI type position encoder, also the number of bits and the encoding scheme must be selected. For the position sensor type parameter these values are combined to one name. E.g. 'SSI-13G' means 13 bit, Graycode SSI sensor, 'SSI-24B' means 24 bit binary encoded SSI sensor.Beside the SSI-xxX, RESOLVER and ANALOG selections this parameter offers the choice 'NONE' which tells the ACU not to read a position encoder at all. With this selection you can tell the ACU if the polarization is not to be controlled by the ACU.If you are using multiturn SSI encoders you will have to scale the reading (See 'Calibration scale' below).
Pre scale offset --- The pre-scale calibration offset is added to the raw position encoder reading before scaling is applied. The pre scale offset is defined as an 8-digit hexadecimal value in normalized position encoder ticks (00000000-FFFFFFFF equivalent to the full range of the encoder (0-360° with single turn encoders).The pre scale offset must be adjusted to avoid any 7FFFFFF to 8000000 overflow within the used range of the encoder. The value is added to the encoder reading, neglecting an overfly eventually occurring. Thus, the offset implements a 360° turnaround automatically.The pre scale offset may be computed and set manually or by assistance of the ACU's automatic calibration function as described below.
Post scale offset --- The post scale calibration offset is added to the position value before the angle value is displayed, but after the scaling is applied. The post scale offset is defined in degrees of AZ/EL/POL.The ACU provides a function to calculate and set both, the pre-scale and the post-scale offset from a known pointing:
1. Set the calibration scale / gear ratio for the axis (this calibration parameter is described with the next paragraph).
2. Set the soft limits of the axis to preliminary values. In most cases this needs not to be very accurate, the ACU needs this information to calculate the pre-scale offset to shift the encoder overflow outside the used range.
3. Optimize the satellite pointing for the reception from a satellite for which the azimuth and elevation values are known.
4. Click to the 'calc' label beside the calibration offset.
5. Enter the known pointing angle for the satellite and click to submit.
6. The ACU calculates and sets the calibration offsets to a value so that the actual pointing is displayed as the angle you entered.

For the azimuth axis there is another offset which also is taken into account, the 'Antenna course'. This value is provided for mobile applications where a compass reading has to be included into the azimuth value.

Calibration scale --- Normally the ACU assumes that the full range of a position sensor corresponds 360°. If you are using a multiturn position sensor or if the position sensor is mounted to the shaft of a gear rather than to the antenna axis directly, the position sensor reading must be scaled. The displayed angle is computed as follows:displayed-value = ((raw-reading+pre-scale-offs) * scale) + pos-scale-offsMathematically a scale value of 1.0 disables the scaling. Beside this, the ACU also accepts the special value 0 to disable scaling at all. If you set 1.0, the ACU performs the scaling with this factor. With the value 0 the scaling is skipped completely, including the conversion of the reading to floating point. This ensures, that the full accuracy is retained in cases where no scaling is necessary.
Sense invert --- With this parameter you easily can reverse the sense of a position sensor. The sense should be as follows:
- Azimuth: The antenna looks more to the west for larger values.
- Elevation: Larger values mean higher elevation.
- Polarization: The feed turns clockwise (when looking through the antenna to the satellite) for increasing values. When operated on the southern hemisphere, the polarization sense must be set the other way round.
Motor driver type --- The ACU knows two different configuration modes to control a motor driver. They are called DIR-START and DUAL-START. In DIR-START mode, the FWD signal switches the motor on/off, the REV signal controls the motor direction. This is the configuration many frequency inverters use. In DUAL-START mode, the FWD signal switches the motor on in forward direction, REV activates the motor in reverse direction. This configuration mode is convenient to control a motor with relays. Beside the modes DIR-START and DUAL-START you may set the motor driver type to NONE which prevents the ACU from controlling the motor at all.
Low speed threshold --- The ACU controls a motor at two speeds. If the actual position is far away from the target value, the ACU commands the motor to use the fast speed. Once the antenna comes close to the target value, the ACU slows down the motor. The low speed threshold sets the angle deviation which lets the ACU use the fast motor speed.
Pointing hysteresis --- The ACU performs the motor control as a closed loop: if the angle reading and the target value differ, the motor is switched on to compensate the difference. If the difference is less than the hysteresis value, the ACU leaves the motor switched off. This prevents the antenna from oscillating around the target value.
Motor timeout --- The ACU monitors the position readings while the motor is running. If there is no change in the position readings for some time, the ACU assumes to motor to be blocked and switches it off. This 'motor timeout' fault must be reset by the operator to release it. A timeout value 0 disables the timeout.
Lower limit --- The minimum target value accepted at the user interface and via remote control. This software limit prevents the ACU from running the antenna to the limit position under normal conditions.
Upper limit --- The maximum target value accepted at the user interface and via remote control. This software limit prevents the ACU from running the antenna to the limit position under normal conditions.

Beacon Receiver

Parameter Name	Description
Beacon RX type	Selects the source of the beacon level the ACU shall use. Available options are SATNMS and VOLTAGE. In SATNMS mode the ACU reads the beacon level from a *sat-nms* beacon receiver via UDP, in VOLTAGE mode the A/D converter input of the ACU is read. Please mention, that in SATNMS mode, the beacon receiver must be set to send UDP datagrams to the ACU/ODM.
Beacon RX IP address	The IP address of the beacon receiver. Applicable only in SATNMS mode.
Beacon RX voltage scale	The scale factor for the analog beacon level input. The value must match the scaling of the beacon level signal.
Beacon RX 0V level	The beacon level which is displayed if the ACU recognizes 0V beacon level input.

Location

Parameter Name --- Description
GPS receiver type --- Defines the type of GPS receiver the ACU uses to read its geodetic location.'NONE' tells the ACU that no GPS receiver is connected. The geodetic position of the Antenna has to be entered manually. The ACU synchronized its internal clock to the CMOS clock chip on the board.'NMEA' tells the ACU to expect messages from a NMEA GPS receiver connected to the serial interface at CON8, pins 1-3. The ACU automatically sets the antenna's geodetic location to the values received and synchronizes the clock to the GPS timestamps. If no NMEA messages are received, the ACU states a fault.
Antenna course --- The Antenna course is an additional offset which is included into the azimuth calibration. It is used for mobile antennas to set the orientation of the antenna without recalibrating it. For stationary antennas this value always should be set to 180°.
Antenna longitude --- The geodetic longitude of the antenna. For a precise orbit to pointing calculation this value should be entered with 0.001° accuracy.
Antenna latitude --- The geodetic latitude of the antenna. For a precise orbit to pointing calculation this value should be entered with 0.001° accuracy.
Antenna abs. altitude --- The absolute altitude over sea of the antenna location.

Orientation

Parameter Name	Description
Compass type	Applicable only for car-mobile variants of the ACU
Inclinometer type	Applicable only for car-mobile variants of the ACU
Nick offset	Applicable only for car-mobile variants of the ACU
Roll offset	Applicable only for car-mobile variants of the ACU

SNMP Control

From Software version 2.1.007 or higher, the sat-nms ACU contains an SNMP agent listening at UDP port 161. The SNMP agent provides a common subset of the MIB-II system / interface parameters and gives full access to the remote control capabilities of the sat-nms ACU with a number of MIB objects placed in the private.enterprises tree.

The actual MIB file defining the ACU's private MIB may be downloaded from the ACU itself by FTP (user 'service', password 'service'). The file 'ACUODM.MIB' contains all necessary information.

Parameter Name	Description
SNMP read community	Sets the SNMP community string expected for read access. The default is 'public'.
SNMP write community	Sets the SNMP community string expected for write access. The default is 'public'.
SNMP trap community	Sets the SNMP community string sent with traps. The default is 'public'.
SNMP traps	This parameter decides if the SNMP traps are enabled or disabled.
SNMP system name	The ACU replies to MIB-II sysName requests with the text entered at this place.
SNMP system location	The ACU replies to MIB-II sysLocation requests with the text entered at this place
SNMP system contact	The ACU replies to MIB-II sysContact requests with the text entered at this place.
MIB File	click here to download the MIB file
SNMP trap IP 1-4	Enter up to 4 trap destination IP addresses (dotted quad notation) to make the ACU sending traps by UDP to these hosts. Setting the parameter to 0.0.0.0 disables the trap generation.

Access Control

User password --- Here you can define the password for the 'user' login. Default password is 'user'. When you are logged in as 'user' you can command the antenna pointing, set the tracking parameters (if applicable) and store / recall targets. You can't modify the setup parameters or issue low level commands on the test page while logged in as 'user'.
Admin password --- Here you can define the password for the 'admin' login. Default password is 'admin'. When you are logged in as "admin" you have full access to all parameters of the ACU, including the setup and the tweaks on the test page.

Setup Page Example