The GX6264 has 64 double-pole, single-throw, normally open (2 Form A) relays. The board organizes the relays into two sections. Each section further organizes the relays into groups of 8. Each group of 8 has a common bus that is accessible by external connection. Each group is a scanner; one and only one relay can be closed at a time in each group. It is not possible to enable two relays simultaneously within a group.
Eight scanner groups and two universal buses permit the user to configure the GX6264 for multiple configurations depending on the test requirements. The scan groups are divided into two identical sections; scan groups A-D comprise Section 1 and scan groups E-H comprise Section 2.
The GX6264 switching board has two main modes of operation: direct-bus mode and universal bus mode.
In the direct-bus mode, each scan group is only used for differential scanning or multiplexing using its common bus. Eight differential channels are available for each scan group.
In the universal-mode, each scan group may be used for differential or single-ended switching. The Universal Bus Mode connects any group to its section's universal bus. There are two universal buses within a group, X and Y. This mode creates a row and a column organization, similar to a matrix. When operating in single-ended switching the maximum number of channels are 128. Each universal bus can be configured for use as a single-ended channel.
The universal and the direct-bus modes can be combined on a group by group basis.
Scan groups A through H provide a common bus. For example, channels 1 to 8 are in group A. Access to the common side of any of the relays is through Group A bus. In this mode, each scan group is only used for differential scanning or multiplexing. Eight differential channels are available for each scan group.
In this mode, each scan group may be used for differential or single-ended switching. The Universal Bus Mode connects any group to its section's universal bus. There are two universal buses within a group, X and Y. This mode creates a row and a column organization, similar to a matrix.
This mode provides the maximum number of channels (128 channels) for programming the board. Each universal bus can be configured for use as a single-ended channel. A cross bar relay alternates between connecting the universal bus high and low rail to either the high or low rail of a group bus. This doubles the number of channels within a group, but it requires the use of the X or Y bus within a section. This single ended mode extends the capability of the instrument to support 16 channels per group.
This mode refers to the use of Direct Bus mode and Combination mode on a group by group basis.