B&K Precision 4079 - Manual - Manual (Page 13)

7
DB-9 pin Name Note
1
2
3
4
5
6
7
8
9
-
TXD
RXD
-
GND
-
RTS
CRS
-
-
Transmit Data
Receive Data
-
Signal ground
-
Request to Send
Clear to send
-
*Note: Use a Null-modem or cross over cable (pin 2 and 3 switched) in order to communicate with instrument. When transmitting
large files via RS232, highest baud rate setting of 38400 is recommended, and number of data points of transfer at any instance
should not exceed 1,000,000 points. If 4,000,000 points are required, multiple transfers are recommended; each time transferring
100,000 points. For optimal speed in transferring large files, GPIB interface is recommended using block transfer (see
Programming Section of this manual).
2.9.1 Communication Speed Chart
The 4076 and 4079 have the capabilities of generating large arbitrary waveforms with up to 4,000,000 points. Due to this
nature, the time it takes to transmit these large waveforms may vary depending on the baudrate and cable used for RS232
interface. As a general reference, provided below is a chart that shows the approximate amount of time it takes to download or
send the waveforms of the indicated sizes at the rated baudrate speed.
Number of data pts.
Baudrates (bps)
400,000 points 1,000,000 points
38400
~30 mins
(sending)
~15 mins
(receiving)
~1hr (sending)
~30mins (receiving)
2.10 RS-232 Configuration
The instrument use 8 data bits, 1 stop bit, no parity and baud rate selectable from 2400 to 38.4K (2400, 4800, 9600, 19200,
38400). By default, the instrument is set at 9600-8-N-1.
When the instrument is in remote mode, it will display the following screen:
This screen comes up whenever there is a transmission process, be it sending or receiving. To return to local mode and exit
this screen, simply press any front panel keys. Only do this when nothing is being transmitted or received from a connected
PC. In the case where a large waveform is being transmitted, please allow AT LEAST 15 seconds or more after the PC
software or program has finished sending BEFORE pressing a key to return to local mode. The instrument requires this time
to completely finish generating/transmitting the waveform.