51404127-100 Honeywell Input module Brand new

The green LED, DS1, on the IOTA adjacent to terminal block TB2 illuminates if either the Series C

system 24V internal system supply or an external user supplied power source is properly

connected to TB2. If this LED does not illuminate, check wiring to TB2, fuse F3, or the field wiring.

If TB2 is not used (no wires attached), then LED DS1 does not illuminate and this is normal.

6.6.3 Examples to illustrate sensor power connections through TB2

Example 1: Sensor powered from Series C System +24 V internal supply.

Connections made through TB1, FLDPWR(x)+ and COMMON(x)

The following figure displays a sample diagram where the sensor is powered from Series C system

+24 V internal supply and the power connections are made through TB1, FLDPWR(x)+ and

COMMON(x).

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Chapter 6 - Series C PIM connectivity

Figure 6.9 Sensor powered from Series C System +24 V internal supply. Connections made through

TB1, FLDPWR(x), and COM(x)

For this type of connection, you need four wires. Two wires provide power to the sensor and the

other two wires connect the pulse output from the sensor to the PIM. This example shows the field

sensor connected to channel 1 but the procedure applies to the remaining channels.

The internal +24 Vdc supply, TB1, and TB2 are used to supply sensor power. This is accomplished

by connecting the corresponding channel’s FLDPWR1+ pin and COMMON1 pin to the positive and

negative power leads of the field sensor respectively. To complete the circuit, place the jumper wire

across the pins of the COM1 terminal block as illustrated in the above diagram so that so field

return is tied to COMMON1.

Install wires at TB2 as illustrated in the above diagram to feed all eight of the FLDPWR(x) to TB1.

There is no need to add individual wires from FLDPWR(x) to the +EXT 12V/24V connector at TB2 as

this is provided by internal copper tracks on the IOTA.

For clarity, the LED DS1 and other components are not shown in the above diagram. See also

figure PIM TB1 pin assignments.

Example 2: Sensor powered from Series C System +24 V internal supply.

Power connections directly made through TB2

The following figure displays a sample diagram where the sensor is powered from Series C system

+24 V internal supply and the power connects are directly made through TB2.