Specifications

20
Magtrol Model DSP6000 Dynamometer Controller
Chapter 5 - The DSP6000 with a PC (Remote Control)
Figure 9. Connector Pin-Out
12345
6789
RX
TX
DTR
GND
The DSP6000 is equipped with an RS-232 (serial)
interface. To select the baud rate:
1. Press SHIFT and release.
2. Press the COM SETUP button.
3. Press the button under the RS-232 display to cycle
through the following available baud rates:
300 2400 9600
600 4800 19200
1200
Other important communication parameters are:
• No Parity
• 8 Data Bits
• 1 Stop Bit
To wire your own serial communications cable, use the
following wiring diagram:
9 Pin
2345
(DSP6000)
9 Pin
3265
(Computer)
A cable may also be purchased from your local
electronics store. A RadioShack #26-152 cable and #26-
264 null modem adapter are known to work. The null
modem adapter must be used on the computer end of
the cable.
ACQUIRING SPEED-TORQUE DATA
Speed-torque data is a fixed-length string in ASCII
format with a floating point decimal. Use the following
string format:
SdddddTdddd.R[cr][lf]
or
SdddddTdddd.L[cr][lf]
where . . .
S = Speed in RPM. No leading zeroes are used.
d = Decimal digit 0 through 9
T = Torque in units selected during setup. The torque
value always contains a decimal point.
L = Counterclockwise dynamometer shaft rotation (left)
R =Clockwise dynamometer shaft rotation (right)
. = Decimal point. The decimal point location depends
on the specific dynamometer and torque range in
use.
NOTE: The [cr] and [lf] characters will
not display.
Example:
If a motor is running at 1725 RPM clockwise, with the
dynamometer loading the motor to 22.6 oz.in., the
DSP6000 will return:
S 1725T22.60R
By manipulating the string, the speed-torque and shaft
direction (if required) can be extracted. Then separate
numerical variables can be assigned to them for data
processing.
SELECTING THE BAUD RATE FOR THE
RS-232 INTERFACE
The DSP6000 communicates with the host computer
through a DB-9 interface connector. The connector pin-
out is: 2-RX, 3-TX, 4-DTR, 5-GND. No other pins are
connected.