How to Read Compax3 Analog I/O With EPL SDO READ?

Beginning with Operating Systems 1.28 (9030/9040) and 2.28 (9630/9640) with the compatible 1.03.08 EPL version, ACR controllers expand support of EPL drive communication and configuration via SDO transfers.

An EPL drive stores current process and device data in the Object Dictionary (OD), including communication parameters, device identification, and specific functionalities of a device. The Object Dictionary is based on CANopen and follows the same format. The OD contains both standardized objects common to all devices and manufacturer specific objects. Each object within the dictionary is addressed using a 16-bit index and an 8-bit sub-index.

ACR ETHERNET Powerlink controllers utilize both Service Data Object (SDO) transfer and Process Data Object (PDO) transfer as methods of exchanging data with other devices. The ACR controller reads and writes data to and from drives using SDO (during network start and set-up) and PDO (periodically during normal operation) without direct interaction by the user or user programs. The ACR9000 manipulates these objects as required automatically, as the underlying method of normal network operation.

EPL Network Parameters
Example program to get Analog input from Compax3:

PROGRAM
P37378=2 : rem node ID of target drive
P37379=8229 : REM object # for SDO, analog in- hex2025 hex=8229dec
P37380=0 : REM subindex object # for SDO, analog in- hex2025 hex=8229dec
p37381=3 : rem object dat type, 16bit integer

_LOOP
DWL 1
GOSUB GETEPL
PRINT "StatusVoltage_AnalogInput0", P37520
GOTO LOOP

_GETEPL
SET 16643 : rem get data
INH 16659 : rem wait until getting data starts
INH-16659 : rem wait until getting data completes
REM once get is complete, data is populated in P37520
RETURN

ENDP

Update for this running constantly is 10-20 Hz. Resolution of the analog input is 0.1vdc. For applications requiring faster update or higher resolution, use Parker I/O expansion.