Site Survey Troubleshooting; Conduct A Site Survey Using Modbus Commands - Banner Sure Cross Performance DX80 Instruction Manual

We recommend keeping the missed packets average to less than 40%. When the network misses more than 40% of the
data packets, the signal is usually too unreliable or obstacles may be interfering with the signal. When Site Survey reports
the missed packets are 40% or higher, improve the radio system performance by:
• Mounting the network's antennas higher,
• Using higher gain antennas, or
• Adding data radios to the network.
Mounting the devices' antennas higher allows the radio signal to clear obstacles in the area and improves the line of sight
®
between Sure Cross devices. Higher gain antennas focus the energy of the radio signal in a specific direction and extend
the signal's range. Using data radios is another option to consider when trying to extend the range of a radio network. For
more information on data radios, please refer to Banner's white paper on range extension on
www.bannerengineering.com/wireless.

3.7.3 Site Survey Troubleshooting

Some tips and tricks about improving radio signal reception may improve the site survey results.
Marginal Site Survey (RSSI) Results. If the distance between devices is greater than 5,000 meters (3 miles) line-of-
sight or objects, such as trees or man-made obstructions, interfere with the path, and the MISSED packet count exceeds
40 per 100 packets, consider the following steps:
• Raise the DX80 units to a higher elevation, either by physically moving the devices or installing the antenna(s)
remotely at a higher position;
• Use a higher gain antenna;
• Decrease the distance between devices; or
• Use data radios to extend the position of the Gateway relative to the host system.

3.7.4 Conduct a Site Survey Using Modbus Commands

Use Modbus commands sent from the host system to start a Site Survey.
To start a Site Survey using a Modbus write holding register command, send a control code of 32 (0x20) and the Node
number 1 through 15 (0x01 to 0x0F) to the Gateway Modbus holding register for I/O 15.
I/O 15
Control Code Data Field
32 Node # 1–15
3.7.4 Example Command
I/O 15
When Site Survey runs, the accumulated results are stored in the Gateway's I/O 7 and I/O 8 holding registers. The LEDs
on the both the Gateway and the Node's front panel display the signal strength for the wireless RF link. The quality of the
communications link is indicated by:
Green LED = excellent signal strength
Amber LED = good signal strength
Red LED = poor signal strength
The signal strength is the transmitted signal strength relative to the ambient RF signal present in a specific location, or
noise floor.
All manuals and user guides at all-guides.com
[15:8]
Control Code
I/O 15 Control Messages
Restrictions Description
Gateway only Enable Site Survey between Gateway and Node defined by the data field. All
error messages from the Gateway are ignored when running Site Survey.
Only one Node can participate in Site Survey at a time. To disable the Site
Survey, use control code 0x20 with Node 0. A Node must be enabled to run
the Site Survey, then disabled before selecting the next Node.
32
www.bannerengineering.com - Tel: 763.544.3164
®
Sure Cross Performance DX80 Wireless I/O Networks
Modbus Register
Modbus Register
[7:0]
Data Field
02
19