Appendix c: expected latency – B&B Electronics ZXT9-IOA-KIT - Manual User Manual
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Manual Documentation Number: ZXTx-IO-x-4113m
57
A
A
p
p
p
p
e
e
n
n
d
d
i
i
x
x
C
C
:
:
E
E
x
x
p
p
e
e
c
c
t
t
e
e
d
d
L
L
a
a
t
t
e
e
n
n
c
c
y
y
Before you lift a finger towards the perfect wireless installation, think about the impact of wireless communications on your
application. Acceptable bit error rates are many orders of magnitude higher than wired communications. Most radios quietly
handle error detection and retries for you - at the expense of throughput and variable latencies.
Software must be well designed and communication protocols must be tolerant of variable latencies. Not every protocol can
tolerate simply replacing wires with radios. Protocols sensitive to inter-byte delays may require special attention or specific
protocol support from the radio. Do your homework up front to confirm th
at your software won’t choke, that the intended radio
is friendly towards your protocol, and that your application software can handle it as well.
Assumptions:
No RF retries.
Units were less than 3 feet apart during the testing in a clean RF environment.
Modbus Mode
Reading Inputs
Setting Outputs
ZXT24-IO-222R2
ZXT9-IO-222R2
ZXT24-IO-222R2
ZXT9-IO-222R2
126 mS
164 mS
68 mS
69 mS
Peer-to-Peer Mode
Latency in Peer-to-Peer Mode
Xtreme Modules
Digital
Analog
ZXT24-IO-222R2
80 mS
126 mS
ZXT9-IO-222R2
115 mS
126 mS