8
Using the Connectors
Some usage scenarios of the microSpider2 I/O connectors are outlined below:
Connect inputs as per manual:
o
Switch, event, counter and quadrature inputs - connected directly to
appropriate input and GROUND.
o
4-20mA
– Connect directly between an available analogue input and
GROUND. External resistors are NOT required.
o
Voltage inputs with a range of up to 2.4V
– connected directly
between an available analogue input and GROUND
o
Voltage inputs with a range over 2.4V
– connected via dividing
resistors (not supplied
– see the manual for details)
“SWITCHED POWER OUT” on I/O Connector 1 can be used to power
sensors from an external power s
upply connected to “EXTERNAL POWER
IN”. The microSpider2 will switch the power to the sensor when required. If an
external power supply is connected, it will also power the microSpider in
preference to its internal battery pack as long as its voltage is above
approximately 7.5V
“OPEN COLLECTOR OUTPUT” on I/O Connector 2 can be used to control
external devices such as samplers and power supplies. When activated, this
output will create a connection to GROUND through a 440 Ohm resistor.
“INTERNAL LOW-VOLTAGE SENSOR POWER SUPPLY” on I/O Connector 2
can be used to power low power sensors directly from the microSpider2
internal battery pack. This output is user settable as either 3.3V or 5V and is
current limited to approximately 100mA. Please note that using this power
supply will increase the system power consumption and reduce the
microSpider2 battery life.
Prior to leaving a site, you must ensure that any unused I/O connector and the
communications connector (see below) are fitted with supplied sealing caps to prevent
contact contamination.