Curtis 1356, Manual, Page: 26 / 58

22 Curtis 1356/1356P CAN Expansion Module Manual,
Rev. A
Virtual Digital Inputs Byte
Each analog inputs also produce a “virtual” digital input response. The status
of the virtual digital inputs in default PDO-MISO mapping is as follows.
PDO1-MISO Byte 3
Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
[Reserved] (0)
Virtual Virtual Virtual Virtual Virtual
Input5 Input4 Input3 Input2 Input1
Status Status Status Status Status
If the input is above the programmed High Threshold, the bit will be set
to 1. If the input is below the programmed Low Threshold, it will be set to 0.
Otherwise, the bit will retain its previous state.
Analog Input High/Low Bytes
The voltage value of the five analog inputs is default mapped in the PDO-
MISOs. Each voltage value requires 2 bytes of the PDO packet.
For each analog input, if Resistive Input Type is enabled and the resistance
is mapped in PDO-MISOs, the value will be returned as ohms, up to 7.5 kΩ.
The value 0xFFFF is interpreted as infinity (wire open).
Encoder Input Bytes
When the Analog Input pair (Analog Input 4&5) is configured as encoder in-
put, the relative PDO bytes will carry the pulse count, RPM value, or position
value of the encoder if they are mapped in PDO-MISOs. The encoder input
type can be configured as follows.
Pulse Count type
In this type, PDO will output the number of the encoder
pulses accumulated. The value is up to 2 29 -1 or down to -2 29
at which point it will roll back to zero.
RPM type
In this type, PDO will send the RPM value (2 bytes, unit in
revolutions per minute).
Position type
In this type, PDO will send the position value (2 bytes, unit
in millimeters).
4 — PDO COMMUNICATIONS