Churchill Nano Link IP67, Technical Manual, Page: 11 / 42

Page 9
Connections to the 7041 controller are via screw terminals, as follows:
Terminals 7 and 8 should be connected to Vin – and + respectively on
Nano_Link
. Terminal 5 can be connected to any
of the digital inputs on
Nano_Link
if required. Terminal 6 can be connected to Analogue 1+ on
Nano_Link
if the
battery volts is to be monitored remotely, with analogue 1- connected to the Analogue – terminal. Do not fit a link
between 1I and 1-. Analogue input 2 can still be used for 0…100mV or 0…20mA signals.
3.3.5 External 5V Source
Nano_Link
can alternatively be operated from an external source of 3.0…5.5V. The supply must be capable of
supplying 1A surge currents.
3.4 Plant I/O
All plant I/O on
Nano_Link
is via screw terminals on two-part connectors. This provides universal connectivity whilst
allowing the unit to be easily replaced if necessary. One connector is allocated for digital I/O and another for analogue
I/O. The pin functions are marked on the top cover.
3.4.1 Digital Inputs
Nano_Link
has 4 identical digital inputs, with a common return, intended for use with volt-free contacts. The input
circuit is as follows:
The inputs are intended for use with volt-free contacts, but can also be used to monitor DC voltages in the range
0…24V. A closed contact (or a voltage less than approx. 1V) is treated as logic ‘1’, and an open contact (or a voltage
greater than approx. 4V) is a logic ‘0’.
The series resistors give protection against EMI and excessive voltages in input terminals. The capacitors serve the dual
purpose of providing a surge wetting current when the input contact first closes and providing switch bounce filtering,
whilst allowing pulses of up to 10pps to be counted.
0V
470K

V+
1M

100

COMMON
RETURN
INPUT
100

10n
10n
M
DIGITALS
M
CO OUTPUTS
INPUTS
CO
O/
P
1 2 3 4 1 2 3 4
I/P
1 2
3 4
5 6
7 8
1 Solar Panel –ve 2 Solar Panel +ve
3 Battery –ve 4 Bve
5 Battery Low Alarm 6 Battery monitor
7 Output –ve 8 Output +ve