MPIControlTimingConfig

Definition

typedef struct MPIControlTimingConfig {
	double	sampleRate;
	int32_t	txTime;
} MPIControlTimingConfig;

Required Header: stdmpi.h

Change History: Added in 04.00.

Description

MPIControlTimingConfig is a structure that contains the controller and SynqNet network cyclic timing configurations.

sampleRate	Number of controller foreground update cycles per second. For SynqNet controllers, this is also the cyclic update rate for the SynqNet network. During the controller's foreground cycle, the axis trajectories are calculated, the filters (closed-loop servo control) are calculated, motion is coordinated, the SynqNet data buffers are updated, and other time critical operations are performed.The default sample rate is 2000 (period = 500 microseconds). The minimum sampleRate for SynqNet systems is 1000 (period = 1 millisecond). The maximum is dependent on the controller hardware and processing load. There are several factors that are considered to find an appropriate sampleRate for a system. The servo performance, the motion profile accuracy, the SynqNet network cyclic rate, the SynqNet drive update rates, controller background cycle update rate, and controller/application performance. For SynqNet systems, select a sampleRate that is a common multiple of the SynqNet drives connected to the network. For example, if the drive update rate is 8 kHz, the appropriate controller sample rates are: 16000, 8000, 5333, 4000, 3200, 2667, 2286, 2000, 1778, 1600, 1455, 1333, 1231, 1067, and 1000.
TxTime	This value determines the controller's transmit time for the SynqNet data. The units are a percentage of the sample period. The default is 75%. Smaller TxTime values reduces the latency between when the controller receives the data, calculates the outputs, and transmits the data. If the TxTime is too small, the data is sent before the controller updates the buffer causing a TX_FAILURE event.

sampleRate

Number of controller foreground update cycles per second. For SynqNet controllers, this is also the cyclic update rate for the SynqNet network. During the controller's foreground cycle, the axis trajectories are calculated, the filters (closed-loop servo control) are calculated, motion is coordinated, the SynqNet data buffers are updated, and other time critical operations are performed.The default sample rate is 2000 (period = 500 microseconds). The minimum sampleRate for SynqNet systems is 1000 (period = 1 millisecond). The maximum is dependent on the controller hardware and processing load. There are several factors that are considered to find an appropriate sampleRate for a system. The servo performance, the motion profile accuracy, the SynqNet network cyclic rate, the SynqNet drive update rates, controller background cycle update rate, and controller/application performance. For SynqNet systems, select a sampleRate that is a common multiple of the SynqNet drives connected to the network. For example, if the drive update rate is 8 kHz, the appropriate controller sample rates are: 16000, 8000, 5333, 4000, 3200, 2667, 2286, 2000, 1778, 1600, 1455, 1333, 1231, 1067, and 1000.

TxTime

This value determines the controller's transmit time for the SynqNet data. The units are a percentage of the sample period. The default is 75%. Smaller TxTime values reduces the latency between when the controller receives the data, calculates the outputs, and transmits the data. If the TxTime is too small, the data is sent before the controller updates the buffer causing a TX_FAILURE event.

MPIControlTimingConfig

Definition

Description

See Also