Delta ASDA-A3 Series User Manual page 905

Absolute System
Descriptions:
When the handshake communication starts, the ABSE signal is triggered.
(1)
After the T
(2)
10
DO3 are switched to ABSQ, ABSR, and ABSD, respectively. If DI4 was in the high-level
state before, it remains in the high-level state when switched to ABSQ (logic high-level
signal). DI4, DO2, and DO3 are dual-function DI/DOs, which means the set functions for
DI4, DO2, and DO3 share the same DI/DOs with ABSQ, ABSR, and ABSD. Pay special
attention to the functions when switching or set these DI/DOs to 0 to disable the set
functions.
If DI4 was in the high-level state and switched to ABSQ after the T
(3)
controller resets this signal to low level, the new signal is interpreted as the data access
command.
After the T
(4)
Now the servo drive triggers the ABSR signal and the controller can access the data.
If the controller cannot detect the ABSR status while it is changing to high level after the
maximum T
communication cable disconnection.
Once the ABSR signal is set to high level, the controller accesses the data, and the ABSQ
(5)
signal is set to high level to notify the servo drive that data was read.
When ABSQ is at high level, ABSR is set to low level after the T
(6)
data for the next bit communication.
When ABSR is at low level, ABSQ is also set to low level and the servo drive needs to
(7)
send the data for the next bit communication.
Repeat steps 3 and 4. Send the absolute position to ABSD for the next bit communication.
(8)
Repeat steps 5 to 7. The controller has read and received the data.
(9)
(10) The third bit data is ready.
(11) After the T
signal, the servo drive sends the ABSW signal (communication error) and stops the
handshake communication.
(12) When the controller receives the communication error signal, it sets ABSE to low level and
prepares to restart the handshake communication.
(13) ABSW resumes to low level after the servo drive receives the ABSE signal.
(14) The controller resumes communication after the T
(15) Repeat step 1.
(16) If no error occurs, the controller completes 80 bits (0 - 79) of the handshake communication
with the servo drive. DI4, DO2, and DO3 then resume their original functions.
Note: if ABSE is set to low level first and then changed to high level, but ABSW does not resume to high
level and the alarm remains on, it means some other errors exist. Check for the following possible
warnings: absolute position lost, low battery voltage level, or absolute position overflows. Restart a
new communication cycle after those errors have been cleared.
10-24
delay time (make sure the ABSE signal is On), the functions for DI4, DO2, and
s
time, the handshake data is ready and the absolute position is sent to ABSD.
Q
time (refer to Figure 10.3.6.1), there may be a communication error such as
Q
waiting time, if the controller has not read the data and triggered the ABSQ
R
delay time, when the
S
time in order to send the
N
time.
B
ASDA-A3