Table of Contents
Advertisement
The End of Line resistor should be set to Y on the jumper setting (see figure 6).
Cables
Two core twisted pair cable is to be used to wire the P2 Network (a screened cable can
be used to offer better protection). P2 Controllers can be further linked together in a
"daisy chain", to a maximum of 16 on the whole network, by wiring A to A and B to B
using the Network terminal blocks of the P2 Controllers.
If the optional screened cable is used then the incoming and outgoing screen can be
fitted to SCR on the Network terminal block. It is important to remember that the
screen needs to be earthed to ground at one end of the network.
A screened cable has advantages over a standard twisted pair cable. Whilst not a
complete guarantee, a correctly fitted screened cable will help protect against induction
from fluorescent lighting, power surges or lightening strikes by safely discharging the
current to earth instead of the circuit board which could lead to damage.
Desktop Reader
The USB Interface can also support a connection to a P2 Desktop Reader which is
connected via the Reader terminal block. The positive and negative terminals from the
P2 Desktop Reader should be wired to the positive and negative connections on the
USB Interface Reader terminal block and the X and Y data connections from the P2
Desktop Reader should be wired to the USB Interface Reader terminal block by linking
X to X and Y to Y.
Figure 7 below shows the layout of the USB Interface including the network
connections and desktop reader ancillary.
LED Indicators
The Reader LEDs
The LEDs inform on the status of the optional P2 Desktop Reader.
A red LED
indicates that there is a short circuit and a green LED indicates that there is data from
the desktop reader.
The USB LEDs
TX (red) and RX (green), advise on whether the PC is transmitting to the USB Interface
(TX) or receiving information from the USB Interface (RX).
The P2 Network LEDs
The green Poll LED signifies that the USB Interface is receiving data from the PC and
the red Data LED signifies that there is data on the P2 network.
13
Advertisement
Table of Contents
