Balluff BIS M-370-000-A02, Manual, Page: 59 / 198

BIS M-62_ MANUAL
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2
Figure 36 - NPN External Trigger Using External Power
2.7.2 Outputs
Two general purpose optocoupled outputs are available on the Processor units with the I/O
option. See par. 2.3.7 for pinout.
The user can activate/deactivate the two outputs through specific commands (see par. 2.7.3
for the specific Command Protocol Reference Manual according to your Processor unit
model).
When connected to an external circuit, the current must enter in O1+/O2+ and exit from O1-
/O2-.
The electrical features of the outputs are:
Voltage Range: 6 ~ 30 Vdc
Maximum Current:
- If externally powered (by the user): 500 mA
- If powered by the Processor unit (pins 1 and 2 of the I/O connector): max. 300 mA
(*)
(*) This is the maximum value of current computed as the sum of both the Outputs! In
fact the output current supplied by the Processor unit is limited. In other words if only
one output is active the maximum current value is 300 mA, but if both the outputs are
active then each Output current must decrease (for example max. 150 mA for each
Output).
Notes
- It should be noted that if the power supply for the I/O is supplied by the Processor unit
(pins 1 and 2), the opto-isolation feature for the Input and Output sections will be lost,
because the ground reference of the I/O and the Processor unit power supply is the
same.
- A device that operates at 200 mA may damage the Digital Output due to inrush
current if a current limiting device is not used and the current exceeds 500 mA (e.g.
an incandescent light).
- The inductive "kick" that occurs when a relay is released (back EMF from a collapsing
magnetic field) can impose a voltage higher than 30 Vdc that may damage the output
transistor. To avoid this potential issue, employ a diode (D1) to clamp the back EMF.
D1 should be a 1N4001 or equivalent.