RoboteQ Dual Channel Digital Motor Controller AX2550 - Manual (Page 131)

AX1500 Motor Controller User’s Manual 131
Controller Commands and Queries
Query Analog Inputs
Description:
This query will cause the controller to return the values of the signals present at its two
analog inputs. If the controller is used in close-loop speed mode with analog feedback, the
values represent the actual speed measured by the tachometer. When used in position
mode, the values represent the actual motor position measured by a potentiometer. In all
other modes, the values represent the measured voltage (0 to 5V) applied to the analog
inputs. The values are signed Hexadecimal numbers ranging from -127 to +127. The -127
value represents 0V at the input, the 0 value represents 2.5V, and the +127 value repre-
sents +5V.
Analog 1 and 2
Syntax:
?p or ?P
Analog 3 and 4
Syntax:
?r or ?R
Reply: nn
mm
Where: nn = analog input 1 (or 3) value, speed or position
mm = analog input 2 (or 4) value, speed or position
Notes:
The command returns a signed hexadecimal number where 0 to +127 is represented by 00
to 7F, and -1 to -127 is represented by FF to 80 respectively.
Query Heatsink Temperatures
Description:
This query will cause the controller to return values based on the temperature measured
by internal thermistors located at each heatsink side of the controller. Because NTC ther-
mistors are non-linear devices, the conversion or the read value into a temperature value
requires interpolation and a look up table. Figure 34 on page 64 shows this correlation.
Sample conversion software code is available from Roboteq upon request. The values are
unsigned Hexadecimal numbers ranging from 0 to 255. The lowest read value represents
the highest temperature.
Syntax: ?m or ?M
Reply: nn
mm
Where: nn = thermistor 1 read value
mm = thermistor 2 read value
Notes:
The hexadecimal format is intended to be deciphered by a microcontroller. When exercis-
ing the controller manually, you may use the Decimal to Hexadecimal conversion table on
page 156.
Query Battery Voltages
Description:
This query will cause the controller to return values based on two internally measured volt-