|
2251A
to 2461C VXI Counter Specification Cross-Reference Guide
Racal Instruments
has discontinued production of all 2251 and 2251A counters. The
new Model 2461C Counter is our closest
replacement for this counter. A specification comparison is presented
below to compare critical specifications of these counters. One
key difference is that the 2461C uses a SCPI command set, while
the 2251 and 2251A both use a native command set.
Our experience
has seen many smooth transitions between the older 2251 products
and the new 2461C. To help with this transition, a code
converter has been developed to show how 2251 commands differ
from 2461C commands.
If you need
additional compatibility information, please contact Racal
Instruments Product Marketing.
|
2461C |
2251A |
| Frequency
Measurement |
|
|
| Channel A Range* |
600uHz
to 200MHz |
588uHz
to 200MHz |
| Channel B Range |
600uHz
to 100MHz |
588uHz
to 100MHz |
| Frequency
Ratio Measurement |
|
|
| Chan. A/Chan. B |
600uHz
to 100MHz |
588uHz
to
100MHz |
| Math
Mode |
(Reading
- X)/Z |
(Reading
- X)*Y/Z |
| Peak
Signal Measurement |
|
|
| Range |
600uHz
to 200 MHz |
588uHz
to
160MHz
(usable to 200 MHz) |
| Dynamic Range |
150mVpk-pk
to 51Vpk-pk |
150mVpk-pk
to 51Vpk-pk |
| Period
Measurement |
|
|
| Channel A Range |
5ns
to 1,700 s |
5ns
to 1,700 s |
| Channel B Range |
10ns
to 1,700 s |
6.25ns
to 1,700 s |
| Autotrigger
Characteristics |
|
|
| Minimum Amplitude |
150mVpk-pk |
150mVpk-pk |
| Frequency Range |
DC,
50Hz to 200MHz |
DC,
50Hz to 160 MHz (usable
to 200MHz) |
| Selectable
Low Frequency for Optimal Speed |
50Hz
or 1kHz (selectable) |
50Hz
(fixed) |
| Hysteresis |
25mV
or 50mV (selectable) |
25mV
(fixed) |
| Measurement
Timeout |
1
to 105s
(programmable) |
Not
available |
| Input
Chars.: Channels A & B |
|
|
| Sensitivity (Sine, 0 to 100 MHz) |
25mVrms |
25
mVrms |
| Sensitivity (Sine, 100 to 160 MHz) |
50mVrms |
50
mVrms |
| Sensitivity (Sine, 160 to 200 MHz) |
75mVrms |
70mVrms |
| Sensititvity (5 ns Pulse) |
75
mVpk-pk |
75
mVpk-pk |
| Dynamic Range |
150mVpk-pk
to 5Vpk-pk |
150mVpk-pk
to 2.5Vpk-pk |
|
Crosstalk (100MHz @ 50W) |
<-36dB |
<-36dB |
| Lowpass
Filter(s) |
Chans.
1 and 2: 50kHz |
Chan.
A only: 50kHz |
| Auxiliary
Outputs |
|
|
| Frequency
Standard |
Yes |
No |
| Trigger
Level |
Yes |
No |
| Command
Language |
SCPI |
Native |
| Pulse
Width Measurement |
5ns
to 20ms |
5ns
to 20ms |
| Rise/Fall
Time Measurement |
20ns
to 20ms |
20ns
to 20ms |
| Measurement
Speed |
40
readings/s |
16
readings/s |
| Measurement
Storage |
14000 |
1 |
| Internal
Timebase |
None,
1ppm or .01ppm |
None
or .01ppm |
| Time
Interval Measurement |
|
|
| Single-shot Range |
0ns
to 800,000s |
-2ns
to 800,000s |
| Averaging Range |
2ns
to 10s |
2ns
to 10s |
| Time
Interval Delay Range |
200ms
to 800ms |
200ms
to 800ms |
| Time
Interval Delay Resolution |
16us |
25.6us |
| Totalize
Measurement Range |
1
to 1012
- 1 |
1
to 1012
- 1 |
| Trigger |
|
|
| Range |
±
5.1V |
±
5.1V |
| Resolution |
2.5mV |
20mV |
| Phase
Range of A Relative to B |
0.1
to 360 degrees |
0.1
to 360 degrees |
|
|
|
|
