Specifications

AM25T Solid State Multiplexer

U-bolts are used to attach the enclosures to a 1.25" NPT pipe. The enclosure

may also be lag-bolted to a wall or similar flat surface.

Fasten the AM25T to the enclosure backplate. Securely fasten the leads to the

strain relief flange running between the AM25T terminal strips and install the

cover to reduce temperature gradients during thermocouple measurements.

3. Datalogger to AM25T Wiring

When powering the AM25T from the same battery as the datalogger, connect

the datalogger to the AM25T as shown in Table 3-1.

Do not reverse the polarity of the +12 Volt and Ground

leads. Damage to the multiplexer, sensors, and

datalogger will occur.

A separate battery can be used to power the AM25T. A separate battery might

be used when the AM25T is installed some distance from the datalogger.

Ground must be connected between the datalogger and the AM25T (Figure 2).

When leads in excess of 152 m (500 feet) are used to connect the datalogger to

the AM25T, it may be necessary to compensate for the drop in RTD excitation

voltage (program examples 2 and 4).

All AM25T inputs are spark gap protected. To ensure that

the spark gaps fire, the large ground wire between the

AM25T and datalogger must not be greater than 152 m

(500 ft). In applications where lighting protection is not

required, limit the cable length between the AM25T and

datalogger to 305 m (1000 ft).

TABLE 3-1. Datalogger to AM25T Wiring

Function AM25T CR10(X) 21X/CR7 CR23X CR1000

+12V Power 12 V 12 V 12 V 12 V 12 V

Power and Shield Ground

G G

Clock CLK Control Port Control Port Control Port Control Port

Reset RES Control Port Control Port Control Port Control Port

RTD Excitation EX Excitation Excitation Excitation Excitation

Analog Ground AG AG

Common High HI Diff. Chan. H Diff. Chan. H Diff. Chan. H Diff. Chan. H

Common Low LO Diff. Chan. L Diff. Chan. L Diff. Chan. L Diff. Chan. L

WARNING

Caution