User guide

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PN 161-09981-007A
January 2010
Wireless I/O Extender User’s Guide
Rcv Rate of 100% will provide approximately 100 Kbaud of bandwidth with an RF data rate of 3 (Radio Transmission
Parameters Menu) and approximately 150 Kbaud of bandwidth with an RF Data Rate of 2.
These numbers are reduced approximately 50% if there are one or more repeaters in the network.
Menu (5): Edit Multipoint Parameters
When installing a Point-to-MultiPoint system, for the system it requires that several parameters be set consistently on
all the radios. This includes RF data rate, Min and Max Packet Size, and FreqKey (Unless it is a repeater using repeater
frequency).
(0) Number Repeaters
Sets the number of repeaters in the system, this setting is critical for transmission timing for the system.
•0 when not using repeaters or diagnostics at the master.
•1 if repeaters are in the system or if running diagnostics at the master.
Note: This should be the same for all the radios in the system.
Note: This should be enabled when running diagnostics from the master.
(1) Master Packet Repeat
Sets the number of times the packet is re-broadcast to the system by the master or repeaters in the system. The remotes
do not acknowledge the packets in a multipoint system, so the higher the value the high the probability of receiving a
successful packet at the remote, but the higher the latency for the repeated data packets.
•0 or 1 if the software protocol being used controls the retries.
This could improve throughput if the system has strong RF links and high data rates.
For lower data rates this is not an optimal setting.
•2 or 3 for most well designed networks.
•4 thru 9 for a robust system where high data throughput is not an issue.
Note: This setting is only used in the master and repeaters in a multipoint system.
(2) Max Remote Retry
Sets the number of times the remote will attempt to retransmit a packet to the master. If the packet is not received
successfully within the number of set retries the remote waits a specied a time from the Retry Odds setting.
Set to a higher value for a better probability of a successful packet to the master with one transmission time, but this could
cause a higher latency for the other remotes in the system.
Note: The remote will stop the retries when an acknowledgement is received from the Master.
(3) Retry Odds
Sets the fallback time algorithm to wait to retry for the remote, to resolve contention to the master.
•A lower setting to assign a lower priority to the remote re-transmitting the data buffer.
his could be used with a remote with a strong RF link to have a lower priority to a remote with a
weaker RF link.
•A higher setting to assign a higher priority to the remote re-transmitting the data buffer.
This could be used with a remote with a weak RF link to have a higher priority than a remote with a
strong RF link.
Note: If Retry Odds is set to 0, the remote’s data buffer will be purged if all the max remote retry were
unsuccessful.