Programmable controller with intelligent positioning I/O modules

An electrical controller for controlling machine motion through a plurality of electromechanical I/O positioning devices, the controller comprising:

• a plurality of satellite I/O modules each connectable to a respective I/O positioning device to generate output drive signals thereto in response to move data, wherein each satellite I/O module requests move data, when needed, by transmitting a move request signal;
• a main processing unit that transmits parameter data and move data and receives status data during I/O operations, the main processing unit including
• memory means for storing the parameter data, which includes data indicating the number of satellite I/O modules, which includes data that selects one of the two modes of axis coupling, at least two of the satellite I/O modules being coupled for directing coordinated motion along respective axes in the first mode of axis coupling, and one or more independent satellite I/O modules directing motion independently along respective axes in the second mode of axis coupling, the parameter data also including data pointers to the locations of the move data,
• the memory means also storing move data as coupled moves applicable to coupled satellite I/O modules and as individual moves applicable to independent satellite I/O modules, and
• processing means coupled to the memory means for transmitting the parameter data and for receiving status data including a data pointer, and in response to the status data, for transmitting move data in one transmission for each plurality of coupled satellite I/O modules and for transmitting move data in a separate transmission for each independent satellite I/O module;
• and
• master I/O processing means electrically coupled to the processing means in the main processing unit to receive the parameter data and electrically coupled to the satellite I/O modules to receive move request signals, the master I/O processing means including
• means responsive to move request signals from any of the coupled I/O satellite modules and from any independent satellite I/O module for transmitting status data to the main processing means that includes a pointer to the move data for the requesting satellite I/O module, and
• means for receiving the move data in response to the transmission of the status data, and in response to the parameter data received previously, distributing the move data received in coupled moves to the respective coupled satellite I/O modules and distributing the move data in independent moves to its associated independent satellite I/O module.

A programmable controller for closed-loop positioning control of machine motion through an I/O positioning device, which moves in response to velocity signals and which generates position feedback signals, the controller comprising:

• a main processor that stores and transmits userprogrammable move data including a programmed position, a programmed velocity and a programmed deceleration for each of a plurality of successive moves;
• and
• a satellite I/O module coupled to the main processor, and coupled to the I/O positioning device to read the feedback signals therefrom and to generate velocity output signals thereto, the satellite I/O module including
• first memory means for storing move data received from the main processor,
• an axis processor coupled to the main processor to receive the move data for successive moves, coupled to the first memory means to transfer the move data thereto, and coupled to the I/O positioning device to receive the position feedback signals and to transmit the velocity output signals, and
• second memory means for storing machine instructions for the axis processor,
• wherein the axis processor is operable to compute the actual velocity for the present move and to detect a programmed velocity for a next move that is less than the actual velocity of the present move, and
• wherein the axis processor is further operable to detect a point of deceleration before reaching the end of the present move and to then apply the programmed deceleration to the actual velocity, so that the next move can be initiated at its programmed velocity.

An intelligent positioning I/O module for real-time closed-loop positioning control of one axis of machine motion, the I/O module being insertable into a rack structure, the I/O module being connectable for communication with a programmable controller main processor, and the I/O module being connectable to a servomechanism controlling motion along the axis, the I/O module comprising:

• memory means for receiving user-selected move data for a present move and user-selected data for a next move from the programmable controller main processor, the user-selected move data for each move including a programmed destination, a programmed velocity and a programmed deceleration;
• input circuit means connectable to a position sensing portion of the servomechanism to receive position feedback signals and to convert such signals to position feedback data;
• output circuit means connectable to drive a servo motor portion of the servomechanism by coupling servo velocity output signals thereto, the output circuit means converting servo velocity output data to the servo velocity output signals that are coupled to the servo motor portion;
• programmed axis processor means coupled to the memory means to obtain the user-selected move data therefrom, coupled to the input circuit means to receive position feedback data and coupled to the output circuit means to generate servo velocity output data thereto to control axis motion;
• wherein the programmed axis processor means is operable to compute servo output velocity data for the present move and to detect a programmed velocity for the next move that is less than the servo output velocity of the present move;
• and
• wherein the programmed axis processor means is further operable to detect a point of deceleration before reaching the end of the present move to then apply the programmed deceleration to reduce the servo output velocity data before it is coupled to the output circuit means, so that the next move can be initiated at its programmed velocity.

An intelligent positioning I/O module for real-time closed-loop positioning control of one axis of machine motion, the I/O module being insertable into a rack structure, the I/O module being connectable for communication with a programmable controller main processor, and the I/O module being connectable to a servomechanism controlling motion along the axis, the I/O module comprising:

• first memory means for receiving user-selected move data for a present move and a next move from the programmable controller main processor, the user-selected move data for each move including a programmed destination, a programmed velocity and a programmed acceleration and deceleration;
• input circuit means connectable to a position sensing portion of the servomechanism to receive position feedback signals and to convert such signals to position feedback data;
• output circuit means connectable to drive a servo motor portion of the servomechanism by coupling servo velocity output signals thereto, the output circuit means converting servo velocity output data to the servo velocity output signals that are coupled to the servo motor portion;
• second memory means for storing a first sequence of axis processor instructions to generate servo velocity output data to the output circuit means to drive the servomechanism in response to the difference between an accumulation of command position increments, and an accumulation of position feedback data received from the input circuit means, the second memory means also storing a second sequence of axis processor instructions to calculate command position increments for the present move based on the programmed destination to be reached at the end of the present move, the accumulation of position feedback data, the programmed velocity for the next move, and the programmed acceleration or deceleration;
• timing means for providing a periodic signal on a preselected time base;
• and
• an axis processor coupled to the timing means, coupled to the first and second memory means and coupled to the input circuit means and output circuit means, the axis processor being responsive to each periodic signal from the timing means to read and execute the first and second sequences of axis processor instructions to generate servo output velocity signals to the servomechanism through the output circuit means and to read position feedback signals from the servomechanism through the input circuit means to provide real-time closed-loop positioning control on the preselected time base, such control including the application of the programmed acceleration or deceleration to change from the velocity of the present move to the programmed velocity of the next move.

A programmable controller for controlling machine motion through a plurality of electromechanical I/O positioning devices, the controller comprising:

• a plurality of I/O circuits each connectable to a respective I/O positioning device to generate output drive signals thereto in response to move data, and to transmit a move request signal when data is needed;
• main processing means for storing and transmitting (i) user-selected parameter data, which includes a pointer to a motion control block of data, (ii) the motion control block of data, which represents manual input motion commands, and (iii) user-selected move data;
• master I/O processing means coupled to the main processing means for receiving the parameter data and the move data and for transmitting a status block of data, and coupled to the I/O circuits for receiving move request signals, the master I/O processing means transmitting the status block of data with a pointer to the motion control block of data in the absence of move request signals from the I/O circuits;
• wherein the main processing means transmits the motion control block of data in response to receiving its corresponding pointer;
• and
• wherein the master I/O processing means is responsive to the receipt of the motion control block of data to coupled manual input motion commands to the I/O circuits, which execute these commands.