©
July 2001
Impro Technologies
Data subject to change without notice
Page 8
CONNECTING THE UNIT
General
The connections to the unit are shown in Figure 2.
Input Power Connections
Power must be connected to the unit only at the terminal block labelled "POWER INPUT".
This input is polarity-sensitive and must be connected as indicated on the PCB by the “+”
and “-“ symbols.
RS485 Communications Connections
All communications cable should be screened. The cable screen should be connected to
the PCB terminal labelled “RS485 ETH”, and this terminal should in turn be connected to a
good EARTH ground. Connect each unit individually to ground to prevent possible ground
loops.
Remote Reader Power Connections
The output power cable to the Remote Reader must be connected at the terminal blocks
marked "REMOTE UNIT 5V OUT". The Remote Readers are generally polarity-sensitive,
and must be connected correctly as indicated using the "+" and "-" symbols.
Remote Reader Communications Connections
When connecting the ImproX DT Terminal to a Remote Reader of types MR, KR, MHR,
KHR and CR, it must be remembered that the "Tx" terminal on the ImproX DT Terminal
must be connected to the "Rx" terminal on the Remote Reader, and vice versa. It is
recommended that the cable screen be connected to the "Remote Unit 5V Out -" terminal
at the ImproX DT Terminal, and to the "POWER -" terminal at the Remote Reader as
shown in Figure 2.
For an Impro 4-Channel UHF Receiver connection, the "Remote Unit 5V Out” terminals
must be connected to the 5V input of the UHF Receiver. The selected channel output from
the UHF Receiver must be connected to the “Comms RX” terminal and the selected
channels “GND” terminal connected to the "Remote Unit 5V Out-“ at the DT.
Cable length
The recommended maximum length of the Remote Reader communications cable is 20
metres.
Jumper Settings
If the unit is the last unit at the end of the RS485 communications bus (i.e. furthest from
the associated controller), and the transmission lines are long or multiple “star”
connections are used, there will be a danger of reflections occurring on the
communications bus and disrupting communications. To prevent this, the jumper located
adjacent to the RS485 Terminal Block on the last unit in the chain must be connected.
NOTE :
This jumper must only be connected at the unit at the end of the bus,
not
at
every unit.
