YASKAWA SGD7S-****20A Series - Transmission Specifications; Calculating the Current Position in Machine Coordinates

6.8 Absolute Encoders
6.8.5 Transmission Specifications
6
Application Functions
6-37
6.8.5 Transmission Specifications
The position data transmission specifications for the PAO (Encoder Divided Pulse Output) signal are
given in the following table.
The PAO signal sends only the multiturn data.
Refer to the following section for the timing of sending the position data from the absolute encoder.
6.8.4
Reading the Position Data from the Absolute Encoder
on page 6-36
Data Format of PAO Signal
As shown below, the message format consists of eight characters: “P,” the sign, the 5-digit multiturn
data, and “CR” (which indicates the end of the message).
6.8.6 Calculating the Current Position in Machine Coordinates
When you reset the absolute encoder, the reset position becomes the reference position.
The host controller reads the coordinate Ps from the origin of the encoder coordinate system. The host
controller must record the value of coordinate Ps.
This section describes the reference position in the machine coordinate system.
The method to calculate the coordinate value of the present position from the origin of the machine
coordinate system is given below.
The current position P
M
in the machine coordinate system is calculated as follows:
P
M
= P
E
- P
S
P
E
= M
×
R + P
O
P
S
= M
S
×
R + P
S
’
Item PAO signal
Synchronization Method Start-stop synchronization (ASYNC)
Transmission Speed 9,600 bps
Start Bits 1 bit
Stop Bits 1 bit
Parity Even
Character Code ASCII, 7 bits
Data Format Refer to Data Format of PAO Signal.
Data Output Period
Each time the SENS_ON command is input after the
control power supply is turned ON
P
+ or −
0 to 9
0 to 9
0 to 9
0 to 9
0 to 9
CR
Multiturn
data (5 digits)
Machine coordinate
Value of
multiturn data
-1
±0
+1 +2
Origin (reference position) Current position
M × R
P
E
PO
PS PM