E2 Wireless I/O Page 13
The power supply input and battery charging are hosted on a 4-way terminal on the bottom edge of the module labeled “Power Supply”.
To allow increased I/O Capacity, a second 4-way terminal labeled “Expansion I/O” provides a +12 Volt supply and RS485 communications for any 115S serial expansion
I/O modules.
Up to three 115S-11, one 115S-12, or one 115S-13 may be powered by the Expansion
I/O Power Connection
The onboard power supply provides up to 1 Amp for battery charging, and up to 1 Amp to supply I/O modules.
E2 Expansion
B A
I/O
+ B
115S- XX
A + B
115S- XX
A +
2.3 Radio
The following radio variants are available in the E2 dependent on the country of operation.
900 MHz Spread Spectrum radio
The radio operates in the 902-928 MHz ISM band and uses frequency hopped spread spectrum modulation, which is a method of transmitting radio signals by rapidly switching the carrier among many frequency channels, using a pseudorandom sequence known to both transmitter and receiver.
There are eight different pseudo random sequences known as “Hops sets”. Each Hop set uses 50 channels and steps through these channels after every transmission.
The receiver is continually scanning all 50 channels and when a valid data packet is heard it locks on to the channel and receives the data.
A spread-spectrum transmission offers some advantages over a fixed-frequency transmission. These are - Spread-spectrum signals are more resistant to narrowband interference, they are difficult to intercept or eavesdropper because of the pseudorandom transmission sequences and transmissions can share a frequency band with other types of conventional transmissions with minimal interference.
