Inclinometer and Encoder FAQ and Boards Information
- Q: 1/ Will the encoder/inclinometer boards lose positioning during power outage; or you lose power while operating.
- A: No you will NOT lose positioning; the Dallas Semiconductor; “Touch Memory” retains positioning. Operationally there is very little difference between this system than an Absolute System; except for increased flexibility & lower cost.
- Q: 2/ Will this system accommodate linear pulse train from linear actuators (TVRO).
- A: YES, it will; the actuator simply has to produce a +5V to indicate “up”; or “cw” rotation.
- Q: 3/ Does the Inclinometer require drive attachment to mast; or boom.
- A: NO; it does not require drive linkage attachment in any way at all. The inclinometer tilt sensor is the only system that will automatically make corrections for boom to mast miss-alignment; as AZ is changed.
- Q: 4/ Does the Encoder require a 1:1 ratio relationship between Mast & Encoder.
- A: NO, the Encoder to Mast ratio can be anything between 1 and 32:1 ratio; depending on the Encoder you chose to install. The number above is based on an encoder with 2048 quadrature counts per revolution.
- Q: 5/ Does my computer has to be turned on to maintain positioning if AZ or EL is changed.
- A: NO. But Encoder/Inclinometer VCC (+5V); must be on to maintain AZ & EL positioning. In fact I never turn my VCC off.
- Q: 6/ Does the Encoder/Inclinometer operate at TTL Levels from the field.
- A: NO; there is a very small single IC device that translates the TTL levels to true RS-232 levels. Thus providing a 20V level change for each data bit produced. This RS-232 Level will allow you to operate from a distance up to 300 meters; (approx. 950 feet).
- Q: 7/ Does the Encoder/Inclinometer require poling to update readings.
- A: NO; The system is updated and displayed each time there is a data bit change.
- Q: 8/ What is the resolution of the system?
- A: The resolution is 0.01deg. for AZ & 0.05deg. for EL when used with F1EHN Tracking System in binary mode for AUTO TRACKING; or Manual Operation.
Resolution is 0.10deg. in both AZ & EL when used with VK3UM Tracking System in BCD mode and AUTO TRACKING. Both F1EHN & VK3UM Freeware Tracking software available off this site.
However, the resolution remains at 0.10deg when used to drive 7 Seg. Display indicators and operated manually.
One consideration concerning inclinometer and encoder Resolution;
Furthermore, resolution is only as good as the Mechanical System controlling the Dish, or Array; as well as on the accuracy YOU used in the initial CALIBRATION of the system. Moreover, it may not always be possible. But I strongly recommend a FULL Scale 360deg calibration using a surveyors protractor compass. The unit I used was accurate to 0.005 degrees; rare and also nice to have Friends that will loan you one; as I did. In any case; a case a full 360deg. calibration is recommended.
It is also recommended that you derive as many quadrature counts from the AZ Encoder as possible. But not exceeding 64,256 quadrature counts in the full 360deg’s. The ratio of revolutions MAST relative to Encoder can be any ratio needed to reach the above number. However, an example would be an US Digital H3-2048, the turns ratio can be 31.375 : 1; with the LS-7084 quadrature converter set to X 1.
- Q: 9/ Are the Encoders & Inclinometers readily available & at what cost.
- A: Yes they are readily available form US Digital as new units with replaceable internal components.
Cost of Encoder (H3-2000; or H3-2048); is $78.00USD + shipping. Inclinometer (T2-7200-D); $98.00USD at. http://www.usdigital.com
- Q: 10/ Do I have to use the US Digital encoder/inclinometer devices.
- A: NO, any linear encoder/inclinometer that generates quadrature pulses can be used.
- Q: 11/ Can I assemble the Encoder/Inclinometer system myself; and/or change the EPROM code.
- A: Yes to all the above. The EPROM code is free and source code is available if asked for. However, the boards for the encoder/inclinometer interface are available from FAR circuits. http://www.cl.ais.net/farcir
Click here to continue on to the next post; which is about Tracking Systems and Using Two or More Dish Controls.