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Chapter 5
Signal Connections
Motion Axis Signals
Caution
Do not connect these outputs to anything other than a +5 V circuit. The output
buffers will fail if subjected to voltages in excess of +5.5 V.
7344 Hardware User Manual
The following signals control the servo amplifier or stepper driver:
•
Analog Output <1..4>—These 16-bit DAC outputs are typically the
servo command outputs for each axis. They can drive the
industry-standard ±10 V output, and can be software limited to any
positive or negative voltage range desired. They also feature a
software-programmable voltage offset.
Although typically used as the command output of an axis control
loop, unused DACs can also function as independent analog outputs
for general-purpose control.
•
Analog Output Ground—To help keep digital noise separate from the
analog DAC outputs, there is a separate return connection. You should
use this analog ground connection and not Digital Ground (digital I/O
reference) as the reference for the DAC outputs when connecting to
servo amplifiers.
•
Axis <1..4> Step (CW) and Dir (CCW)—These open-collector signals
are the stepper command outputs for each axis. The 7344 controller
supports both major industry standards for stepper command
signals—step and direction, or independent CW and CCW pulse
outputs.
The output configuration and signal polarity is software programmable
for compatibility with various third-party drives, as follows:
–
When step and direction mode is configured, each commanded
step (or microstep) produces a pulse on the step output. The
direction output signal level indicates the command direction of
motion, either forward or reverse.
–
CW and CCW mode produces pulses (steps) on the CW output for
forward-commanded motion and pulses on the CCW output for
reverse-commanded motion.
In either case, you can set the active polarity of both outputs to
active-low (inverting) or active-high (non-inverting). For example,
with step and direction, you can make a logic high correspond to either
forward or reverse direction.
The Step (CW) and Dir (CCW) outputs are driven by high-speed
open-collector TTL buffers that feature high sink current capability.
5-4
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