B&K Precision 4034 - Manual - Manual (Page 19)

19
6. RS-232 Interface - This is a standard RS-232 port used for remote interface. Null modem or cross
serial cable is required to communicate with a PC via this port.
7. Earth GND - This screw is the earth ground that is tied to the chassis.
8. AC Power Connector - Used to connect power cable to AC line source.
9. Fuse Box - Fuse compartment. For replacement, use T1A, 250V fuse only.
10. Cooling Fan - To ensure proper cooling, please leave room between the fan output and other objects
with at least one feet distance.
11. SYNC OUT - (Model 4034 only). 50
Ω TTL sync output for channel 1.
12. TRIG IN and SYNC OUT - (Model 4034 only). TRIG IN and SYNC OUT BNC connectors for
channel 2. SYNC OUT is a 50
Ω TTL level signal. TRIG IN accepts maximum ± 15 V.
3.5 Output connectors
The pulse generator output circuits operate as a 50
Ω voltage source working into a 50 Ω load. At higher frequencies,
un-terminated or improperly terminated output cause aberrations on the output waveform. In addition, loads less than
50
Ω reduce the waveform amplitude, while loads more than 50 Ω increase waveform amplitude.
Excessive distortion or aberrations caused by improper termination are less noticeable at lower frequencies.
To ensure pulse integrity, follow these precautions:
1. Use good quality 50
Ω coaxial cable and connectors.
2. Make all connections tight and as short as possible.
3. Use good quality attenuators if it is necessary to reduce pulse amplitudes applied to sensitive circuits.
4. Use termination or impedance-matching devices to avoid reflections.
5. Ensure that attenuators and terminations have adequate power handling capabilities.
If there is a DC voltage across the output load, use a coupling capacitor in series with the load. The time constant of
the coupling capacitor and load must be long enough to maintain pulse flatness.
Impedance Matching
If the waveform generator is driving a high impedance, such as the 1 M
Ω input impedance (paralleled by a stated
capacitance) of an oscilloscope vertical input, connect the transmission line to a 50
Ω attenuator, a 50 Ω
termination and to the oscilloscope input. The attenuator isolates the input capacitance of the device and terminates
the waveform generator properly.
3.6 MENU Keys
These keys select the main menus for displaying or changing a parameter, function or mode. Below is the hierarchy
and selections of the menu tree.
MENU TREE
- PARAM
o PERIOD | FREQ
o WIDTH | DUTY
o DELAY
o INDEP | CH1 (When CH2 is selected only)
o SINGLE | DOUBLE
- OUTPUT
o HILVL
o LOLVL
o PREDEF
 ECL