ECATReadSdo

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Function Block - Reads a 32-bit word from I/O nodes using a CANopen SDO read command.

Inputs

Input	Data Type	Range	Unit	Default	Description
Execute	BOOL	FALSE, TRUE	N/A	No default	On the rising edge of Execute, an SDO read command is issued. The function block only handles one SDO command at a time. If Execute is toggled quickly so that another rising edge occurs before the SDO command has completed, the function block does not issue a second SDO command.
Index	INT	No range	N/A	No default	The object directory index of the data to be read. See: Communication SDOs. Manufacturer specific SDOs. Profile specific SDOs. To read/write an SDO object with an index greater than 16#7FFF (32767), the value must be entered in this form: `any_to_int(index # in hex format)`. Example: `any_to_int(16#8321)`.
SubIndex	SINT	No range	N/A	No default	The sub-index of the object directory variable to be read. See: Communication SDOs. Manufacturer specific SDOs. Profile specific SDOs. To read/write an SDO object with an index greater than 16#7FFF (32767), the value must be entered in this form: `any_to_int(index # in hex format)`. Example: `any_to_int(16#8321)`.
Size	SINT	1 to 4	N/A	No default	The size (i.e., number of bytes) to read.
DeviceAddress	INT	-32768 to +32767	N/A	No default	The EtherCAT address of the device from which data is read from. The first node usually has the value 1001. The second node usually has the value 1002. Use the members of the EtherCAT structure to specify a device's address to Create Variables.

Outputs

Output	Data Type	Range	Unit	Description
Done	BOOL	FALSE, TRUE	N/A	Indicates whether this function block has completed without error.
Error	BOOL	FALSE, TRUE	N/A	Indicates whether this function block has completed with error.
ErrorID	DINT	No range	N/A	The SDO call error result, if Error is TRUE. See EtherCAT Error Codes. Upon success, Error is set to 0 (zero).
Value	DINT	No range	N/A	The value of the object directory variable being read. Value is only set when an SDO read command has successfully completed.

Remarks

This function block uses and reserves the EtherCAT SDO Channel.
The SDO Channel remains reserved until the done output is TRUE.
This FB should be called at each cycle until either the Done or Error output is TRUE.
If it is not called at each cycle, the rest of SDO communication (e.g., the AKD GUI Views) is blocked.
Using this FB in SFC P0 or P1 steps is not recommended because these steps are executed only once.
If this FB is used in P0 or P1, then it must be used in an SFC N step to ensure the FB completes.

Is typically used to query the status of inputs.
See When can I expect my SDO command to be completed? in the FAQs on how to set up the update rate for SDO communication.
See EtherCAT Function Blocks that Work with SDOs about function blocks used to work with drive or remote I/O parameters that are not supported by ML and MC function blocks.

State Diagram

Figure 1: ECATReadSDO State Diagram

Figure 2: ECATReadSdo

EtherCAT Error Codes

Click to see the Error Codes List

Value Dec (hex)	Error Code	Description
0	ECERR_OK	The SDO call succeeded.
1000 (0x3E8)	ECERR_DEVICE_ACTION_IS_INVALID	The requested Device Action is invalid.
1003 (0x3EB)	ECERR_DEVICE_ACTION_MINIMUM_ONE_NODE_REQD	A minimum of one device must be present in the EtherCAT network.
1004 (0x3EC)	ECERR_DEVICE_ACTION_MINIMUM_ONE_DC_NODE_REQD	A minimum of one Distributed clock capable device must be present in the EtherCAT network.
107 = 0x6B	ECERR_INVALID_ARRAY_SIZE	The size of the connections is too small. When the array size is smaller than the number of bad connections: The array is filled with the data to the size of the array. The error ECERR_INVALID_ARRAY_SIZE is set. In this scenario, the output ConnectionCount is set to the size of the array and it is smaller than the number of actual bad connections.
1792 (0x700)	ECERR_DEVICE_ERROR	EtherCAT device is not accessible.
1794 (0x702)	ECERR_DEVICE_INVALIDCMD	Invalid mailbox command.
1795 (0x703)	ECERR_DEVICE_INVALIDINDEX	An invalid value for the Index input was specified.
1796 (0x704)	ECERR_DEVICE_INVALIDACCESS	Reading of the variable is not permitted.
1797 (0x705)	ECERR_DEVICE_INVALIDSIZE	An invalid size for the parameter was specified.
1798 (0x706)	ECERR_DEVICE_INVALIDDATA	Invalid parameter value(s) in SDO index and/or sub-index.
1799 (0x707)	ECERR_DEVICE_NOTREADY	Device is not in a ready state. The network is not in operational.
1800 (0x708)	ECERR_DEVICE_BUSY	Device is not available to respond.
1801 (0x709)	ECERR_DEVICE_INVALIDCONTEXT	Device responded with an illegal error code, indicating the command is not allowed under the present conditions.
1802 (0x70A)	ECERR_DEVICE_NOMEMORY	EtherCAT mailbox is out of memory or device is out of disk space.
1803 (0x70B)	ECERR_DEVICE_INVALIDPARM	EtherCAT mailbox request was not valid.
1804 (0x70C)	ECERR_DEVICE_NOTFOUND	EtherCAT device not found.
1805 (0x70D)	ECERR_DEVICE_SYNTAX	An unexpected error occurred.
1810 (0x712)	ECERR_DEVICE_INVALIDSTATE	The EtherCAT device is in an invalid state.
1817 (0x719)	ECERR_DEVICE_TIMEOUT	The EtherCAT device failed to respond, timing out.
1826 (0x722)	ECERR_DEVICE_INSERTMAILBOX	Error while inserting the mailbox command into internal FIFO.
1827 (0x723)	ECERR_DEVICE_INVALIDOFFSET	An invalid value for the SubIndex input was specified.
1828 (0x724)	ECERR_DEVICE_UNKNOWNMAILBOXCMD	The master sent an unknown mailbox command to the slave.
1829 (0x725)	ECERR_DEVICE_ACCESSDENIED	Device responded with an invalid access error code, indicating the command is not allowed.
1832 (0x728)	ECERR_DEVICE_INVALIDADDR	The specified EtherCAT node address is invalid.
1836 (0x72c)	ECERR_DEVICE_NOT_A_FSOE_MASTER	Device is not a FSoE master.
1837 (0x072D)	ECERR_DEVICE_DISCONNECTED	The EtherCAT device is disconnected.
1920 (0x780)	ECERR_DEVICE_PARAM_ACCESS_ERROR	Unknown error occurred while accessing parameter.
1921 (0x781)	ECERR_DEVICE_PARAM_NOT_FOUND	Parameter was not found.
1922 (0x782)	ECERR_DEVICE_PARAM_NOT_INTEGER	Parameter is a floating-point value. Integer value required.
1923 (0x783)	ECERR_DEVICE_VALUE_IS_NEGATIVE	No negative values allowed. Value specified was negative.
1924 (0x784)	ECERR_DEVICE_VALUE_OUT_OF_RANGE	Value is out of data-range.
1925 (0x785)	ECERR_DEVICE_VALUE_GREATER_THAN_MAX	Value bigger than maximum.
1926 (0x786)	ECERR_DEVICE_VALUE_LOWER_THAN_MIN	Value lower than minimum.
2048 (0x800)	ECERR_CLIENT_ERROR	Error in Mailbox response to a previously sent mailbox command.
2049 (0x801)	ECERR_CLIENT_TIMEOUT	The SDO command timed out.
2050 (0x802)	ECERR_CLIENT_ INVALIDPARM	An invalid value was specified.
2051 (0x803)	ECERR_CLIENT_ INVALIDSIZE	An invalid value for the size input was specified.

FBD Language Example

FFLD Language Example

IL Language Example

Not available.

ST Language Example

(* Read PL.KP on first AKD Drive on EtherCAT network *)
Inst_ECATReadSdo(TRUE, 16#3542, 0, 4, 1001 );
IF Inst_ECATReadSdo.Done OR Inst_ECATReadSdo.Error THEN
   Inst_ECATReadSdo(FALSE, 16#3542, 0, 4, 1001 );
   PositionProportionalGain := Inst_ECATReadSdo.Value;
END_IF;