Curtis 1353 - PDO1-MISO and PDO2-MISO Status Data; Analog Input and Encoder Data Interpretation

4 — PDO COMMUNICATIONS
pg. 21
Return to TOC Curtis 1353 CANopen Expansion Module Manual – June 2017
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 output limit value: 0 – 255 = 0% – 100%.
BDI
e 1353 can get the BDI value from PDO2-MOSI. is byte is a percent of the battery state of
discharge: 0–100 = 0–100%.
Inputs 1–9 Status Bytes
e 1353 monitors the inputs connected to the nine drivers. e status of these inputs appears in this
bit with Input 1 being the LSB of Byte 1 and Input 8 being the MSB of PDO1-MISO Byte 1 and Input
9 being the LSB of PDO1-MISO Byte2. A status of 1 (bit set) indicates the input is active (pulled
high to B+). e upper 7 bits of Byte 2 are unused and set to 0.
Virtual Digital Inputs Byte
e analog inputs also produce a “virtual” digital input response. e lower 6 bits of PDO1-MISO Byte
3 represent the status of the six virtual inputs associated with the six analog inputs; Analog Input 1 is
the LSB. e upper 2 bits are unused and set to 0. If the input is above the High reshold (set using a
Curtis programmer or an SDO) the bit will be set to 1. If the input is below the Low reshold, it will
be set to 0. If the input is between the two thresholds, the bit will retain its previous state.
Analog Input High/Low Bytes
If the voltage input type is enabled, the 0–15V scale is returned as 0.01 volt per count. For example,
15V is returned as 1500. is requires 2 bytes of the PDO data packet per input.
If the resistive input type is enabled, the value will be returned as ohms, up to 7.5 kΩ. If the pin is
open, the value will be returned as 0xFFFF (65535), which will be interpreted as innity (open pin).
When analog input pairs (1&2 or 3&4) are congured as encoder input, the relative PDO bytes
will carry the pulse count, RPM value, or position value of the encoder. e encoder output can be
congured as the following types, using a Curtis programmer or an SDO.
Pulse Count type
In this type, PDO will output the number of the encoder pulses accumulated. e value is signed and
thus can count up to 2
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-1 or down to -2
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at which point it will roll back to zero. In PDO2-MISO,
for Encoder 1, byte 1 is the lowest byte of pulse count and byte 4 is the highest byte. For Encoder 2,
byte 5 is the lowest byte of pulse count and byte 8 is the highest byte.