Curtis 1352 eXm Manual, R e v. D 3
Output as an Active High digital input
Each output can be also be used as a digital input. Each input is digitally filtered
to eliminate switch “bounce” or noise in the signal. The eXm has internal resistor
pull-downs to B– to provide active high to B+ inputs (standard Curtis input
format). The inputs utilize Schmidt Trigger logic to provide signal hysteresis,
further improving noise immunity and reducing faulty readings.
Analog inputs
The eXm has three analog inputs that are scaled to read 0–30 volts. The analog
channels are read 1000 times/second by a 12-bit ADC, resulting in a resolution
of about 0.7 millivolts. Independently adjustable filters ensure a smooth signal.
RTD/resistive sensor inputs
Analog Inputs 1 and 2 can be used with resistive sensors, such as RTDs (Resistive
Temperature Devices).
Virtual Digital Inputs
The three analog inputs are also sensed and decoded as if they were digital inputs.
A unique feature of these digital inputs is that the active high/low thresholds are
completely programmable. Thus, these inputs can be used with analog sensors
to detect conditions like over/under pressure, high/low level points, etc.
CANopen Convenience
The eXm is CANopen compliant, responding to the standard NMT, PDO, and
SDO communications as well as the CANopen DS301-required identity and
standard objects. The Curtis CANopen extensions allow additional features,
such as OEM and User default configurations and time-stamped fault logging.
The eXm will receive* a single PDO and respond* with a single PDO.
Simplifying the VCL interface to the module, the PDO-RX (MOSI) mapping is
fixed while the PDO-TX (MISO) allows several fixed mapping setups.The PDO-
TX (MISO) can be set to cyclic or event driven. All programmable parameters
and viewable values within the eXm are accessible by standard SDO transfer.
The eXm provides CANopen safety and security features, such as
Heartbeat and Error Message. A time period watchdog will shut down the
drivers if new PDOs are not received in proper cyclic timing.
Familiarity with your Curtis eXm module will help you install and operate it
properly. We encourage you to read this manual carefully. If you have questions,
please contact the Curtis office nearest you.
* NOTE: MOSI (Master Out Slave In) = RX (Server to Client)
MISO (Master In Slave Out) = TX (Client to Server)
1 — OVERVIEW
