IAI America XSEL-S - Manual (Page 28)

2. Specification
22
2.1.4 Input and Output Timing (SIO Type)
The response time (Time it takes RC controller to respond back to XSEL controller's query) can be
calculated by the formula below:
Response time [msec] = Yt + Xt + 2 × (Mt + n) + Command processing time
Mt = 10 [msec] × m : SIO Link (Modbus) Cycle time
m : Number of link axes
n : (Maximum axis number + 2) /2…………………………… (Decimals to be rounded down)
Yt : SEL Program ĺ RC Controller transmission delay time… 1ms or more (It may increase due to
number of executed SEL programs or
number of effective axes.)
Xt : RC Controller ĺ SEL Program transmission delay time… 2ms or more (It may increase due to
number of executed SEL programs or
number of effective axes.)
Notice : x If the number of the control axes is big, the response time is longer since n is
increased.
x Yt and Xt may fluctuate depending on the number of executed SEL programs or
number of effective axes.
x The time that the command reaches the RC controller after SEL Command
execution is approximately the half of the response time.
x When a communication error is generated, the SIO Link Cycle Time (Mt) may be
longer since a retry or axis disconnection recovery treatment is necessary to be
conducted.
SEL Program
RC Controller
Yt : SEL Program
→ RC Controller transmission
delay time
Mt+n : SIO Link
(Modbus) Cycle time
+ X-SEL internal
delay time
X-SEL
Controller
Sending to and
receiving from
RC Controller
Command processing
time
(Operating time, etc.)
Xt : SEL Program
→ RC Controller
transmission
delay time
Mt+n : SIO Link
(Modbus) Cycle time
+ X-SEL internal
delay time