GAI-Tronics 12578-002 Monitored Input Module (MIM) - Manual (Page 4)

Pub. 42004-711L2B
Model 12578-002 Monitored Input Module (MIM) Page 4 of 12
f:\standard ioms - current release\42004 instr. manuals\42004-711l2b.doc
01/09
Installation Guidelines
1. Notify plant personnel of a system shutdown prior to servicing the unit.
2. Disconnect power before installing or removing the MIM.
Mounting
To install the module into the Snaptrack slide either the right or the left edge of the module into the top
groove on the track. On the opposite side, press firmly on the top and bottom corners of the module until
they snap into the groove. Carefully press from each corner toward the center and simultaneously snap
the edge firmly into place.
Power
After the PCBA is installed onto the Snaptrack, 12 V dc power is brought in from the equipment rack
power supply and terminated on TB9 (PWR IN). The positive leg is connected to TB9-1 (+) and the
return leg is landed on TB9-2 (-). An earth ground is connected to TB9-3 (EGND). TB9 is paralleled
with TB10. TB10 (PWR OUT) may be used to distribute power to additional Snaptrack modules.
The equipment rack power supply is not part of the 10457 Series Card Rack Assembly. The card rack
power supply is not used to provide power to the Snaptrack modules. An additional power supply must
be included in the cabinet to support these modules.
Connect the return leg of the power supply to earth ground at the supply terminals. N OTE : The ground
reference for this assembly and the card rack must be identical.
Data Communication Line
Terminal block TB12 has been provided to distribute the RS-485 data communication line to additional
Snaptrack modules. If there are no additional Snaptrack modules, connect a 47207-151 150-ohm, ½ watt
terminating resistor (sold separately) across TB12 of the 69251-xxx, or install a jumper across the pins of
P2 on the 69248-xxx CPU PCBA.
CAUTION
The RS-485 line is polarity-sensitive. Be sure to maintain circuit polarity throughout installation.
N OTES :
1. The conductor terminated on TB12 should be a twisted pair.
2. Only one termination is to be applied to an RS-485 circuit - either a 150-ohm resistor across TB12, or
a jumper across the pins of P2 on the 69248-xxx CPU PCBA.