AMCI SMD34K, User Manual

Page: 17 / 100

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SMD34K User Manual
SMD34K S
PECIFICATIONS
17
Available Discrete Inputs (continued)
Stop Jog or Registration Move Input
When an input is configured as a Stop Jog or Registration Move Input, triggering this input during a Jog
Move or Registration Move will bring the move to a controlled stop. The controlled stop is triggered on an
inactive-to-active state change on the input. Only Jog Moves and Registration Moves can be stopped this
way, all other moves ignore this input.
If the unit was order with an integral encoder, the encoder position data will be captured when the DC input
makes an inactive-to-active transition if it is configured as a Stop Jog or Registration Move Input. The
encoder position data is not captured if a Jog or Registration Move is not in progress. If you want to capture
encoder position data on every transition of a DC input, configure it as a Start Indexer Move Input.
Capture Encoder Position Input
As described in the Start Indexer Move Input and Stop Jog or Registration Move Input sections above, an
SMD34K can be configured to capture the encoder position value on a transition of a discrete DC input.
General Purpose Input
If your application does not require one or more of the inputs, you can configure the unused inputs as General
Purpose Inputs. The inputs are not used by the SMD34K, but their on/off state is reported in the network data
and is available to your host controller.
Optional Encoder
The SMD34K can be ordered with an integral encoder. The encoder is typically used for position verification
and stall detection. Additionally, an input can be configured to capture the encoder value when the input
makes an inactive to active transition. This captured value is written to the host controller. Two encoder
options are available:
Incremental Encoder
The incremental encoder can be programmed to 1,024, 2,048, or 4,096 counts per turn. The SMD34K has an
internal thirty-two bit counter associated with the encoder.
Absolute Multi-turn Encoder
The absolute encoder has a fixed resolution of 2,048 counts per turn. The absolute encoder is a multi-turn
device that encodes a total of 2
21
turns, yielding a full thirty-two bits of position resolution. The absolute
encoder can be used for position verification and stall detection, but its primary advantage is that it eliminates
the need to home the axis after cycling power to the drive.
Like many intelligent absolute encoders on the market today, the absolute encoder in the SMD34K uses a bat-
tery backed circuit to count zero crossings while power is removed from the rest of the device. The battery
life is 10 years in the absence of power. The circuit will accurately track position as long as the shaft acceler-
ation is limited to 160,000 degrees/sec
2
, (444.4 rev/sec
2
), or less.