Specifications

Crestron TPMC-3X Isys™ 2.8” Handheld WiFi Touchpanel
Appendix: Roaming with a TPMC-3X
What is roaming?
Roaming is the seamless integration of multiple access points, which allows a
TPMC-3X to remain connected to the Wi-Fi network while physically moving
between coverage areas of multiple access points.
Setup Considerations
When setting up multiple access points with the same SSID and the same
encryption/authentication protocols, there are a few things which might present
issues when using a Wi-Fi remote.
The TPMC-3X will occasionally scan the wireless airspace and eventually detect the
second CEN-WAP when in range of both units. The TPMC-3X will make an
intelligent decision regarding when to disconnect from the first CEN-WAP and
connect to the second, based upon comparing the signal strength of the two units.
Because the units are autonomous, the authentication and network negotiation has to
happen on the second CEN-WAP after the connection to the first CEN-WAP has
been disconnected. This will result in a slight downtime. This duration of this
downtime is not standard because your network conditions will vary from site to site
and network conditions will effect connections to the control system and possibly
authentication to the network.
The installer should locate CEN-WAP access points with consideration of the
following environmental factors::
• Density of building materials
• Interference from adjacent 802.11abg networks (at 2.4 GHz or 5 GHz)
• Antenna placement
• Many other site specific factors
Arrange access points so that overlapping coverage areas are limited to locations
where TPMC-3X use will be rare. For example, a staircase or hallway would be a
good place to allow overlap, so when the unit does the switch from one WAP to the
other, as the end user is not in a place that will be affected by the disturbance of the
connection.
Proper channel selection should be observed as well. For example, both CEN-WAP
units should not be put on channel 6, as this will create interference on that channel.
For 802.11g, the only non-overlapping channels are 1, 6 and 11. For 802.11a, each
channel is non-overlapping and can be used individually. Refer to the latest version
of the Best Practices for Installation and Setup of Crestron RF Products Reference
Guide (Doc. 6689).
Recommendations
Unlike other Crestron remotes, which require dedicated access points, the
TPMC-3X can share access points with other network devices but should not exceed
the access point manufacturer’s specifications for wireless clients. A good
troubleshooting tip when encountering wireless problems with any Crestron Wi-Fi
product is to provide a dedicated access point to see if this resolves your issues.
Operations Guide – DOC. 6789F Isys™ 2.8” Handheld WiFi Touchpanel: TPMC-3X • 43