Operator`s manual

Number

Label Description

Number

Label Description

65 Ch11Lo Channel 11 Low 72 Ch24Hi Channel 24 High

66 BHi B-bus/Ch33 High 73 Ch25Hi Channel 25 High

67 Ch14Hi Channel 14 High 74 Ch27Hi Channel 27 High

68 Ch16Hi Channel 16 High 75 Ch29Hi Channel 29 High

69 Ch18Hi Channel 18 High 76 Ch31Hi Channel 31 High

70 Ch20Hi Channel 20 High 77 DHi D-Bus/Ch35 High [1]

71 Ch22Hi Channel 22 High 78 +5V +5V unregulated supply

[1] D-Bus is not available when using an Isothermal Terminal Block (SMX40T).

Table 3-1. The Scanner’s DB-78 connector pin assignments.

ChxHi, ChxLo - These are the channel positive and negative terminals for all group channels, respectively. It starts

with Ch1Hi/Lo and ends with Ch32Hi/Lo. Depending on the Scanner configuration, these lines are routed to the bus

terminals AHi/Lo, BHi/Lo, CHi/Lo, or DHi/Lo.

AHi, ALo - These are the A-bus positive and negative terminals respectively. The channels positive and negative

lines may be routed to these lines depending on Scanner configuration. In the Universal mode, it is also possible to

route bus pairs to other bus pairs.

BHi, BLo - These are the B-bus positive and negative terminals respectively. The channels positive and negative

lines may be routed to these lines depending on Scanner configuration. In the Universal mode, it is also possible to

route bus pairs to other bus pairs. In TwoWire mode these are also Ch33Hi/Ch33Lo lines.

CHi, CLo - These are the C-bus positive and negative terminals respectively. The channels positive and negative

lines may be routed to these lines depending on Scanner configuration. In the Universal mode, it is also possible to

route bus pairs to other bus pairs. In TwoWire mode these are also Ch34Hi/Ch34Lo lines.

DHi, DLo - These are the D-bus positive and negative terminals respectively. The channel positive and negative

lines may be routed to these lines depending on Scanner configuration. In the Universal mode, it is also possible to

route bus pairs to other bus pairs. It is important to note that when using the Isothermal Block the DHi and DLo

terminals should not be used, and a configuration involving them should not be selected with the exeption of the

ColdJunction configuration which selects the Cold Junction temerature sensor of an SMX40T. Therefore

configurations such as FourGroups should not be used, and when selecting Universal configuration, care must be

taken not to include these terminals. Since these lines also serve as Ch35Hi/Ch35Lo, avoid selecting Ch35 when

using the Isothermal Block (SMX40T) In TwoWire mode.

TrigComm - This is the TrigIn and TrigOut return terminal. Both of these signals are referenced to it. All three

signals associated with the trigger circuitry, TrigComm, TrigIn, and TrigOut are optically isolated from the rest of

the terminals in the DB-78 connector.

Signametrics 14