RoboTel Firmware documentation¶
Contents:
Introduction¶
RoboTel was build by Halfmann and upgraded by AIP in 2020/2021. All important electronic components have been replaced by Beckhoff modules. A central Beckhoff PLC controls the servo controllers, DC controllers, temperature sensors and digital I/Os.
Please read the Safety Instructions before operating the telescope.
RoboTel is a robotic telescope, which means that it is either operated remotely or autonomous. It has limited capabilities to be operated by hand mainly for maintenance, testing and commissioning. There are several levels of protection to prevent remote operation of the telescope.
Pressing the emergency stop deactivates all electric circuits and all motors.
Deactivating the brake clearance prevents movement of azimuth and elevation.
Turning the power switch to off also prevents movement of azimuth and elevation.
Switching to manual operation on the pendant control overrides remote operation.
Be aware that many settings except for the emergency stop can be enforced by the TwinCAT3 IDE in debugging mode.
Logical Structure¶
The telescope electronics have been split up into several components for security, safety and design reasons.
Main Cabinet¶
The main cabinet contains the main PLC and the high voltage components for the servo drivers, which are also situated here. Azimuth, elevation and de-rotator drives are powered and controlled from here as well as the hydraulic system. The yellow modules are responsible for the safety system TwinSAFE.
The other subsystems like the telescope cabinet and the weather station are connected here using EtherCAT over fibre connections.
The main cabinet features the following controls on the side:
green button: start the hydraulic pumps
red button: stop the hydraulic pumps
black button: reset the TwinSAFE system if power key is off otherwise reset an error.
white light: indicates if power is ready
brake clearance: open (I) or lock (O) the brake for azimuth and elevation.
power key: enable high power for the drives.
red light: indicates an error.
emergency stop button: deactivate all systems
Telescope Cabinet¶
The small cabinet at the telescope contains all DC drivers for the covers, M2(focus) and M3 (Nasmyth mirror). It also interfaces all temperature sensors and digital inputs for the limit switches.
An EtherCAT fibre link connects to the dome control.
Dome Control¶
The dome azimuth and the dome shutters are controlled from here. See also Dome Operation
Weather Station¶
The weather station has analog inputs for the wind, temperature und humidity sensors and a digital input for the rain sensor.
Design issues¶
The RoboTel telescope has some design flaws originating from the original design by Halfmann. See Design Issues for a detailed analysis and potential upgrades of the system.