Curtis 1352 - Page 21

18
Curtis 1352 eXm Manual, R ev. D
PDO-TX (MISO): Type 2 Driver Current
Byte 1 Byte 2* Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 Byte 8
Inputs 1-6
Status
Virtual
Inputs +
2 (upper
nibble)
Driver 1
Current %
(0-100)
Driver 2
Current %
(0-100)
Driver 3
Current %
(0-100)
Driver 4
Current %
(0-100)
Driver 5
Current %
(0-100)
Driver 6
Current %
(0-100)
PDO-TX (MISO): Type 3 Driver 1-3 Information
Byte 1 Byte 2* Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 Byte 8
Inputs 1-6
Status
Virtual
Inputs +
3 (upper
nibble)
Driver 1
PWM %
(0-100)
Driver 1
Current %
(0-100)
Driver 2
PWM %
(0-100)
Driver 2
Current %
(0-100)
Driver 3
PWM %
(0-100)
Driver 3
Current %
(0-100)
PDO-TX (MISO): Type 4 Driver 4-6 Information
Byte 1 Byte 2* Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 Byte 8
Inputs 1-6
Status
Virtual
Inputs +
3 (upper
nibble)
Driver 4
PWM %
(0-100)
Driver 4
Current %
(0-100)
Driver 5
PWM %
(0-100)
Driver 5
Current %
(0-100)
Driver 6
PWM %
(0-100)
Driver 6
Current %
(0-100)
* Note that the PDO type is declared in the upper nibble of Byte 2
Output Command Bytes
The drivers are closed-loop controlled, either for current or voltage. This byte sets
the output command as a percent of the programmed maximum value; 0 – 255
= 0% – 100%. The maximum output is set by the Output Max Value parameter
in either current or volts, depending on the Driver Mode parameter setting.
Inputs 1–6 Status Bytes
The eXm monitors the inputs connected to the 6 drivers. The status of
these inputs appears in this byte with Input 1 being the LSB. A status of 1 (bit
set) means the input is active (pulled high to B+). The upper 2 bits are unused
and set to 0.
Analog Input High/Low Bytes
These bytes respond with either the voltage reading (in hundredths of a volt)
or the resistance (in ohms) depending on whether the input’s Analog Source
is enabled. If the Analog Source is enabled for an analog input, the internal
pull-up is activated allowing the measurement of resistive sensors at the input.
In this case the PDO reading will naturally be in ohms. Analog Input 3 does
not have an Analog Source (pull-up) and thus will always read in volts.
Virtual Inputs Byte
The analog inputs also produce a “virtual” digital input response. The lower
3 bits represent the status of the three virtual inputs associated with the three
analog inputs; Analog Input 1 is the LSB. The upper 5 bits are unused and set
to 0. If the analog input is above the High Threshold parameter the bit will be
set to 1. If the input is below the Low Threshold, it will be set to 0. If the input
is between the two thresholds, the bit will retain its previous state (hysteresis).
4 — PDO COMMUNICATIONS