Measurement Computing LGR-5320 Series - Manual (Page 16)

LGR-5320 Series User's Guide Functional Details
16
Analog input SE and DIFF channel configurations
Single-ended analog channels 0–3
CH0H = channel 0 SE
CH1H = channel 1 SE
CH2H = channel 2 SE
CH3H= channel 3 SE
Single-ended analog channels 8–11
CH0L = channel 8 SE
CH1L = channel 9 SE
CH2L = channel 10 SE
CH3L = channel 11 SE
Single-ended analog channels 4–7
CH4H = channel 4 SE
CH5H = channel 5 SE
CH6H = channel 6 SE
CH7H=channel 7 SE
Single-ended analog channels 12–15
CH4L = channel 12 SE
CH5L = channel 13 SE
CH6L = channel 14 SE
CH7L = channel 15 SE
Differential analog channels 0–3
CH0H /CH0L through CH3H /CH3L
Differential analog channels 4–7
CH4H /CH4L through CH7H /CH7L
You can configure all LGR-5320 Series analog input channels for voltage input ranges of ±10 V, ±5 V, or ±1 V.
The LGR-5327 and LGR-5329 also support a ±30 V voltage input range.
Unused analog input channels can either be left floating or connected to an AGND pin.
When using the ±30 V input range with the LGR-5327 and LGR-5329, keep source impedance and source
capacitance as small as possible to minimize settling time, gain, and bandwidth errors.
When connecting differential inputs to floating voltage sources in the ±10 V, ±5 V, ±1 V ranges, the user must
provide a DC return path from the low channel (CHxL) connector of each differential input to ground. To do
this, simply connect a resistor from the CHxL connector of the differential inputs to AGND. A value of
approximately 100
kΩ can be used for most applications.
 On the LGR-5325, the
AGND and GND terminals are tied together internally. These grounds are electrically
isolated from the EGND (earth ground) terminal block pin.
 On the LGR-5327, the
AGND, ENC, and GND terminals are tied together internally. These grounds are
electrically isolated from the EGND terminal block pin.
 On the LGR-5329, the
AGND, ENC, and GND terminals are tied together internally. These grounds are
electrically isolated from the EGND and the IGND (isolated ground) terminal block pins.
Trigger input
The LGR-5320 Series supports the following trigger modes to accommodate certain measurement situations.
 External digital trigger
 External analog trigger (single-channel)
 Digital pattern trigger
The LGR-5327 and LGR-5329 also support multichannel analog trigger mode.
To manually trigger an acquisition, press the TRIG/EVENT button.
Digital and analog triggers connected
The input of the digital trigger and the output of the single-channel analog signal comparator are connected
directly to hardware circuits to provide low-latency triggering. Latencies should be low (around 1.5 µs).
External digital trigger
A digital (or TTL-level) trigger starts an acquisition when the trigger condition is met at the DTRIG terminal.
When using digital triggering, the TTL trigger signal on the DTRIG connector is for a trigger condition. When
the selected condition occurs, it is the trigger event.
If the LGR-5320 Series device is ready for a trigger, then the trigger event occurs.