AMCI SV160E2, Руководство пользователя, Страница: 16 / 120

SV160E2 S
PECIFICATIONS
SV160E2 User Manual
ADVANCED MICRO CONTROLS INC.
16
Absolute Encoder
The absolute encoder has a fixed resolution of 16,384 counts per turn. The absolute encoder is a multi-turn
device that encodes a total of 2
17
turns, yielding a full thirty-one bits of position resolution. The Profile and
Encoder positions are reported back with a range of ±2
30
counts, and range from -1,073,741,824 to
1,073,741,823
Like many intelligent absolute encoders on the market today, the absolute encoder in the SV160E2 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.
Stall Detection
A motor stall is detected when the Encoder Position differs from the calculated Profile Position by a pro-
grammed amount. This amount is programmed with the Maximum Position Error Limit parameter. Stalls can
occur because the programmed Continuous Torque Limit or Peak Torque Limit values are set too low, the
move’s programmed acceleration or deceleration values are set too high, or the loads’ torque requirements
have increased due to a mechanical change in the system.
When a stall is detected:
1) The Stall_Detected bit is set in the data reported to the host controller.
2) The Profile Position is set equal to the Encoder Position.
3) The SV160E2 preforms an immediate stop. The rate of deceleration during an immediate stop is
programmable with the Immediate Stop Deceleration parameter. The immediate stop deceleration can be
programmed from 1,500,000 steps/sec
2
to 15,999,000 steps/sec
2
. The SV160E2 will stop all motion
immediately if the Immediate Stop Deceleration parameter is set to zero.
4) Once the immediate stop completes, the SV160E2 checks the difference between the Encoder Position and
calculated Profile Position. If the error is less than the programmed Maximum Position Error Limit
parameter the motor will stay enabled. If the error exceeds the Maximum Position Error Limit parameter,
the motor is disabled and a Position_Invalid bit is set to “1” to signal the host controller of the error.
Available Discrete Inputs
The standard SV160E2 has four discrete DC inputs, Inputs 1 - 4. The SV160E2-STO has two discrete DC
inputs, Inputs 1 and 2, in addition to its two STO inputs. These discrete DC inputs accept a nominal 12 to 24
Vdc signal and their functionality is fully programmable. The active state of each input is also programmable.
Programming their active states allow them to act as Normally Open (NO) or Normally Closed (NC) contacts.
All of these inputs are open collector sinking and share their common connection. The remainder of this sec-
tion describes the available functionality.
Home Input
Many applications require that the machine be brought to a known position before normal operation can
begin. This is commonly called “homing” the machine or bringing the machine to its “home” position. An
SV160E2 allows you to define this starting position in two ways. The first is with a Position Preset command.
The second is with a sensor mounted on the machine. When you define one of the inputs as the Home Input,
you can issue commands to the SV160E2 that will cause the unit to seek this sensor. How the SV160E2 actu-
ally finds the home sensor is described in the reference chapter
Homing an SV160E2 starting on page 41.
CW Limit Switch or CCW Limit Switch
Each input can be defined as a CW or CCW Limit Switch. When used this way, the inputs are used to define
the limits of mechanical travel. For example, if you are moving in a clockwise direction and the CW Limit
Switch activates, all motion will immediately stop. At this point, you will only be able to jog in the counter-
clockwise direction.