Clear-Com HX System Frames - Manual (Page 46)

6.7.1 Modes for General Purpose Inputs (GPIs)
General-purpose inputs (GPIs) operate in either of two modes:
• Opto-isolated mode, which requires the externally connected equipment to provide
the current to power the general-purpose input.
• Non-isolated mode, which means that the externally connected equipment is not
required to power the general-purpose input. A voltage output on the GP IN
connector supplies the current.
To select a mode, move the J1 jumper on the CPU rear card to one of two positions (The J1
jumper is located on the inner-frame side of the DB-25 connector):
1. For Opto-isolated mode, fit the J1 jumper across pins 1 and 2.
2. For Non-isolated mode, fit the J1 jumper across pins 2 and 3 (This is the default
mode, when the matrix frame leaves the factory).
Opto-isolated mode
Figure 13: Opto-isolated connection to Eclipse GPI connector
In this mode, a DC voltage of between 7 and 24 volts is required at the EXTVIN+ pin with
relation to the EXTVIN– pin. To cause an input to detect an active signal, current must flow
from the relevant input pin.
The external device should draw no current to cause an inactive input and at least 5 mA to
cause an active input. The opto-isolator drive line contains a 1.5 kOhm resistor to limit the
current through the opto-isolator. Therefore the input pins can be connected directly to the
EXTVIN– level to cause an active input.
The voltage level at the external input pin should not be allowed to go below EXTVIN– or
above +6 V with respect to EXTVIN–.
Note:
The Logic 1 input (external input 1) must be shorted to ground to render the Logic 1 signal
active.
46 Eclipse HX Matrix Frame Installation Guide