Rockwell Automation 56RF RFID System User Manual - Manual (Page 46)

46 Rockwell Automation Publication 56RF-UM001A-EN-P - October 2011
Chapter 5 Mechanical Installation
Spacing Next to Metal
Surfaces For the square transceiver, the communication distance will drop significantly
when the distance between the transceiver and any surrounding metal is 30 mm
(1.2 in.) or less. For the rectangular transceiver, the communication distance will
drop significantly when the distance between the transceiver and any
surrounding metal is 50 mm (2 in.) or less.
Figure 13 - Tranceiver Spacing with Metal Surfaces
Transceiver Field Maps The transceiver has a three-dimensional RF field emanating from its sensing
surface. The field consists of a main center lobe and a secondary side lobe.
The RF tags must enter the RF field once, stay long enough to complete the read
and write cycles, and then to leave the field smoothly and efficiently.
Ideally, the RFID tag should pass through the widest section of the main lobe.
This maximizes the time the transceiver has for reading and writing. Avoid the
top of the field, and avoid the side lobes.
The preferred direction of travel is for the tag to pass across the RFID sensor
surface. The tag can also approach the sensor surface directly and then move away
directly backwards or to the side.
Figure 14 shows the field map of the 65mm x 65mm transceiver.
(30 mm)
or more
Metal
(50 mm)
or more
Metal
Square Transceiver Rectangular Transceiver