TopBox Technical Manual

Control Software

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Motor Control

The two filter wheels and the autoguider linear positioner have nearly identical programmable control units which communicate with a control computer through RS-232 serial ports. In the TopBox electronics a single serial line from the control computer is daisy-chained to all three controllers. A terminal application on the control computer can connect to the TTY interface of any one of the three motor controllers to transmit text commands from the keyboard. Each motor controller supports editing, storage, and execution of control programs as described in detail in the Orientalmotor Alpha Step Operating Manual  (pdf).

Under WinXP on the RRRT PC, a Desktop Shortcut icon opens a HyperTerminal application configured for TTY communication with the motor controllers, as shown in Fig. 1 below.

Fig. 1. Sample TTY session with the TopBox motor controllers.

Listings of the Motor Control Programs developed for the TopBox were copied and pasted from HyperTerminal TTY sessions showing connections to the three motor controllers. This direct ASCII terminal interface is the most simple and direct way to operate the filter wheels and the autoguider positioner.

Focus Control

The JMI autoguider focuser is motor driven and has an encoder for absolute or relative postioning. An RS-232 serial line from the control computer is connected to the SmartFocus controller box, which is mounted inside the TopBox electronics enclosure. The controller box has manual pushbutton controls, but it is normally operated from the control computer by serial commands from JMI's standalone basic focuser control software GUI. The main camera control application (MaxImDL) can also provide the autoguider focus control interface through an ASCOM driver. Configuration of the JMI SmartFocus software is shown in Fig. 2 below.

Fig. 2. JMI SmartFocus software configuration for the TopBox autoguider focuser.

Last modified: Nov 15, 2012
David McDavid