RoboteQ Dual Channel Digital Motor Controller AX500 - Manual (Page 110)

Serial (RS-232) Controls and Operation
110 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
Important Notice
On the AX500, the number returned by the ?a command must be divided by eight to obtain
the actual Amps value
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 60 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 126.