CONFIGURATION
+5V ENABLE JUMPER
Pin 49 on all of the 4I24M I/O connectors can either be grounded or connected to system +5V
through afuse. +5V isprovided onpin49to supplypowerto I/Omoduleracks.Thisoptionisselected
by the position of the shorting jumper on jumper block W5. When the jumper is in the left hand
position, fused +5V power is routed to pin 49 on the I/O connectors. When W5 is in the right hand
position,pin49 isusedasanadditionalground.Thisisthedefault positionofthe +5V enablejumper.
Note that the +5V fuse is rated at 1Ampand can be replaced without soldering. Replacementpart
numberisLittleFuse PN250001.
PIN 1 OPTION JUMPERS
Pin 1 is used bysome8 and16 I/O module racks as anadditional5V power source, but is used as
an I/O bit by24 module racks. Jumper blocks W2,W3, and W14 allow pin 1 to be connected to either
+5V or theappropriate I/O bit.Jumper W3selects theoption for connector P1, jumper W2selects the
optionforconnectorP2,andjumperW14selectstheoptionforconnectorP3.
When W2, W3, or W14 are in the left hand position, power is routed to pin 1 of the associated
connector. This istheappropriate setting for most 8and 16module I/Oracks. Notethat power to W2,
W3, and W14 comes from power option jumper W5, which must be in the left hand position in order
tosupplypowertoI/Omoduleracks.
When W2, W3,or W14 are in theright hand position, pin 1 is an I/O bit. This is the appropriate setting
for 24 moduleI/O racks. This is also the default positionofthepin1 option jumpers.
GROUND OPTION JUMPERS
Normally all even pins of the 4I24M 50 pin I/O connectors are grounded at the 4I24M. In some
circumstances, this maycause ground noise to be conducted into the system ground. All I/O ground
linescanbedisconnected at the4I24Mifdesired.
Jumper blocks W1,W4, and W15 select whether or not the even I/O pins are grounded. Jumper W4
selects the option for connector P1, jumper W15 selects the option for connector P2, and jumper W1
selects the option for connector P3. When W1, W4, or W15 are in the left hand position, all even pins
of the associated connector willbe disconnected from ground. When W1, W4, or W15 are in the right
hand position, alleven pins ofthe associated connector will be grounded at the 4I24M. This is default
settingofthegroundoptionjumpers.
Page 9
4I24M USER'S MANUAL
