RoboteQ AX3500 Query Analog Inputs, Query Heatsink Temperatures, Controller Commands and Queries

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.

On controllers prior to RevB, querying Analog inputs 3 and 4 will return a meaningless number.

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 38 on page 68 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 170.

AX3500 Motor Controller User’s Manual 145