The GTX2200 is a Dual Channel Universal Time Interval Counter in a 3U PXI form factor, while the GC2200 is a Dual Channel Universal Time Interval Counter in a PCI form factor. The card has three BNC connectors (input channels A and B and External Clock) and a DIN-6 connector providing connection for External ARM input and TTL Gate output signals.
The input impedance for each channel is independently selectable for High impedance (1 MOhm) or Low Impedance (50 Ohm). Both input channels are capable of measuring frequencies from DC to 225MHz, while Channel A is capable of measuring frequencies from DC to 1.3GHz for the GC2220/GTX2220 and DC to 2GHz for the GC2230/GTX2230. The GC2220/GC2230/GTX2220/GTX2230 models reports 10 digits per second of gate time with 100pS resolution while the GC2210/GTX2210 has 8 digits per second of gate time with 10nS resolution.
All GC22x0/GTX22x0 models support an auto trigger level that automatically searches for the best trigger level before each measurement. Trigger level can also be set manually from –5.0V to +5.0V with resolution of 0.04V.
The GC2200/GTX2200 uses unique reciprocal measurement techniques and achieves high-resolution measurements on low frequency signals. A reciprocal counting technique results in high-resolution measurements on lower frequency signals without sacrificing measurement time. Reciprocal counting provides a fixed number of digits of resolution for all frequencies rather than a fixed resolution in Hz for the same gate time. For example, the GC2220/GC2230/GTX2220/GTX2230 provides 10 digits of resolution for frequencies from 1Hz to 100MHz in one second of gate time.
Measurement arming is a programmable mechanism that creates a “time window” for explicitly selecting specific events. The arming window is defined by events (signal transitions) applied to the External Arm input.
The counter contains a Programmable Built-in calibration circuitry that does the following:
Automatically calibrating the interpolators.
Automatically calibrating the Channel-to-Channel timing skews.
Compensate for the differential non-linearity inherent in analog time-measurement circuitry
Provides verification of the board operation.
Calibration mode can be set to either Continuous, Once or Off.
The figure below shows the GTX2200 with its front panel connectors.
GTX2200 Board Side View
The figure below shows the GC2200 with its front panel connectors.
GC2200 Board Side View