▪ The maxMaster setting will revert to its default value of
▪ The Max info frames will revert to 10.
▪ The device instance will revert to its default of 4194302.
▪ The device name will revert to WEB-[ModelName].
▪ The values of automac min_mac and max_mac will be
reset to 1 and maxMaster, respectively.
Pressing Service Button during Normal Operation
During normal operation of the controller, a short press (< 1
sec) of the Service Button will cause a Service Pin Message
(BACnet WhoAmI as a Private Transfer (SerialNo. = 130)) to
BACnet MS/TP Interface
The controller features an RS485 interface (WEB-RL6N:
terminals 62, 63, and 64; WEB-RS5N: terminals 40, 41, and
42) suitable for BACnet MS/TP communication. The
terminal block containing it is black. The cable length
affects the baud rate. See Table 9
Table 9. Baud rate vs. max. cable length
9.6, 19.2, 38.4, 57.6, and 76.8
The controller supports auto-baud rate adaption for
BACnet MS/TP communication at all of the
aforementioned baud rates (default: 38.4 kbps).
For information on wire gauge, max. permissible cable
length, possible shielding and grounding requirements,
and the max. number of devices which can be connected to
a bus, refer to standard EIA-485.
Connecting to BACnet MS/TP Buses
The controller communicates via its BACnet MS/TP
interface with other BACnet MS/TP-capable devices (e.g.,
other room controllers or MS/TP controllers). In doing so,
the following considerations should be taken into account.
▪ Max. BACnet MS/TP bus length (= "L" in Fig.17): See
▪ Twisted-pair cable, e.g.:
J-Y-(St)-Y 2 x 2 x 0,8;
CAT 5,6,7 cable – use only one single pair for one
Belden 9842 or 9842NH;
and daisy-chain topology.
▪ Must conform to EIA-RS485 cabling guidelines and
ANSI/ASHRAE Standard 135-2010.
▪ Max. no. of BACnet MS/TP devices per BACnet MS/TP
channel (interface) of the plant controller: 32 unit loads.
(Each WEB-RxxN controller represents ¼ of a unit load,
and auto MAC addressing supports a max. of 62
addresses). Effectively, the maximum possible number
of BACnet MS/TP devices (= "N" in Fig.17) per channel of
the Master, incl. the Master itself, is 64.
max. cable length (L)
(3600 ft) 1200 m
SPYDER MODEL 5 ROOM CONTROLLERS − INSTALLATION GUIDE
maxMaster is set by default to 32 devices (this is
because some plant controllers support only 32
devices). In the event that you have a plant controller
capable of supporting more than 32 devices, it will
therefore be necessary for you to increase the
maxMaster setting to the actual required number of
devices (e.g., to 64). Refer to the IRM BACnet Device
Manager – User Guide (EN2B-0414GE51) for more
information on how to do this.
Depending upon your actual performance needs
and required communication rates, we recommend
connecting a lower number of BACnet MS/TP
devices per channel.
CIPer Model 50
Fig. 124. Connection to a BACnet MS/TP Bus
NOTE 1 : If any of the devices are electrically isolated, it is
recommended that those devices be connected to
NOTE 2 : The 120-Ohm termination resistor must be
inserted directly into the terminals of the final
BACnet MS/TP device.
NOTE 3 : If shielding is used, the shielding of each
individual bus segment should be separately
connected at one end to earth.
31-00281ES-01 (EN1B-0664GE51 R0819)