6 |
6.View the Radio Retries and No Ack counts at the point of maximum RSSI level. They should be the same or lower than the previous reading.
(Main Menu > Performance Information > Packet Statistics > Wireless Packet Statistics)
If the RSSI peak results in an increase in the Radio Retries and No Ack counts, the antenna may be aimed at an undesired signal source. Try a different antenna orientation.
Tips for Improving Data Throughput
Some suggestions are offered below for maximizing the throughput of the radio system. It is important to realize that an exact formula for every radio system cannot be given. Much depends on the number of radios contained in the radio system, the size of data strings being sent, the type of data being sent, zone quality (interference potential) and data speed. You should find several items here, however, that can be applied to your radio system.
To Maximize Throughput of Data and Reduce Latency Time
▪(AP only) Increment the Hop Time to the maximum of 28 msec. This lowers the overhead, since it stays longer on a channel. The drawback is that if a particular channel becomes blocked, it will take longer to hop to another channel.
(Main Menu>Radio Configuration>hop Time)
▪Match the buffer sizes and hop times to accommodate the majority of message sizes. For example, a 7 msec hop time is best suited to short data bursts, such as in telemetry applications. A 28 msec hop time is better suited to large data strings, such as sending Web pages over the radio link.
The following table offers suggested Hop Time settings for four different message sizes.
Hop Time | FEC Status* | Bytes per |
(msec) |
| Packet |
28 | OFF | 325 |
| ON | 151 |
14 | OFF | 139 |
| ON | 59 |
7 | OFF | 45 |
| ON | 11 |
*FEC ON is generally not recommended if optimal throughput is desired. The transceiver
NOTE: Reprogramming does not work over the air when the settings Hop Time=7, FEC=On and Encryption=On are used at the AP.
| Chapter 6 Installation |
