Specifications

ISTCD Detector Personality Module (ISTCD DPM), Continued
The Board ID switch shown in figure 2-13 indicates the board number for
the I2C bus. A diagram of how to set the switch is shown on the board.
Each equipped DPM must have a unique board ID
Board ID Switch
A Detector Personality Module is designed to process the signals for two
sets of four thermistor beads. The usual configuration of a TCD in the
Maxum analyzer is to have sets of four thermistor beads, one of which
acts as a reference for the other three. However, in certain situations it
may be desirable to have more than three beads use a single reference.
In other situations only one bead may be needed for a reference.
Occasionally, this could lead to needing additional detector and DPM
hardware.
Reference Select
Switches
The ISTCD is designed to allow the user to partially configure which
reference to use for a particular thermistor bead. This allows for greater
flexibility and reduced hardware costs in some situations.
Either or both of two different beads from the Left/Upper TCD may be
configured to use the reference for the Right/Lower TCD (see figure 2-13
for connector locations). By setting the Reference Select switches, the
Left/Upper beads 1 and 3 may be configured to either Left/Upper or
Right/Lower reference. Note that Left/Upper bead 2 is hard wired to the
Left/Upper reference (bead 2 is selected because it is mounted closest
to the Reference bead in an analytical module).
The diagram on the ISTCD board shows how the switches are set.
Rotating a switch to the right connects that bead to the Left/Upper
reference (the traditional configuration). Rotating the switch to the left
connects the bead to the other reference, Right/Lower.
Note: Rotation of the switch is identified by the small point on the switch,
not the line used to insert a screwdriver to turn the switch. See below.
Rotated Left (Right/Lower Ref) Rotated Right (Left/Upper Ref)
Figure 2-14: ISTCD DPM Connections and Board ID
2-22 A5E31405710001