4.0 COMMUNICATIONS
4.1 Fiber Optic Settings
A set of dip switches (S1) is located on the side of the
module. Dipswitch 10 is used to select the data output
format of the fiber optic port. Many products in the field
today are connected to the existing URTD module. This
module supports 11 RTDs providing only one Auxiliary RTD
to the user. To minimize the effort of replacing an exist-
ing module with a URTDII module, dipswitch 11 selects a
legacy mode that provides data in the same format as the
existing URTD module. Expanded mode adds the 2nd Aux
RTD, case temperature and hottest RTDs from each group
of RTDs. Table 5 shows the selection of this switch:
Table 5, Dips Switch Settings
Dipsw10
Mode
OFF
11 RTDs (Legacy Mode)
ON
12 RTDs, Case, Hottest (Expanded)
4.2 Modbus
4.2.1 General Modus Description
The URTDII can also be used as a stand-alone device
that communicates on a Modbus network. A bidirectional
RS485 port is provided on the bottom of the unit. The fol-
lowing describes the configuration of the Modbus param-
eters.
4.2.2 Addressing
A set of dip switches (S1) is located on the side of the
module. These switches set the Modbus address/configu-
ration. Dipswitches 1 to 8 represent the binary address of
the URTDII. Dipswitch 1 is the most significant address bit
and dipswitch 8 in the least significant bit. Table 6 shows
an abbreviated example of the addressing. Valid addresses
range from 1 to 254. See notes below about reserved
addresses.
Address 00
otee:
N
is a broadcast address and should not
be used in a typical Modbus system. If this address
is selected it will put the URTDII module in a mode
provided exclusively for IMR systems. Please refer to
IMR Documentation for further information.
Address 255
otee:
N
is a reserved address. Normal Modbus
commands will not be interpreted correctly while the
unit is set to this address. In this mode the URTDII
should not be connected to a network because the
network protocol is not being handled. The URTDII
will respond to any message it received with a mini-
mum of a prompt character potentially disrupting any
other communications on the network.
Address
Dipsw0
Dipsw1
Dipsw2
Dipsw3
Dipsw4
Dipsw5
Dipsw6
Dipsw7
Dipsw8
0
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
1
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
2
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
OFF
...
254
ON
ON
ON
ON
ON
ON
ON
ON
OFF
255
ON
ON
ON
ON
ON
ON
ON
ON
ON
Table 6, Modbus Address Selection Settings
8
IL02602013E
Universal Resistance Temperature
November 2010
Detector (RTD) Module II
IL02602013E - November 2010 - www.eaton.com
