The following table shows the data types of the ctrlX Data Layer and the mapping to Node-RED (javascript) as well as to the types of the IEC61131-3 programming language of the PLC app.
| Data Layer | Javascript | IEC61131-3 |
|---|---|---|
bool8 |
boolean |
BOOLEAN, BIT |
int8 |
number |
SINT |
uint8 |
number |
USINT, BYTE |
int16 |
number |
INT |
uint16 |
number |
UINT, WORD |
int32 |
number |
DINT |
uint32 |
number |
UDINT, DWORD |
int64 |
BigInt |
LINT |
uint64 |
BigInt |
ULINT, LWORD |
float |
number |
REAL |
double |
number |
LREAL |
string |
String |
STRING |
arbool8 |
object (Array of number) |
ARRAY OF BOOLEAN, ARRAY OF BIT |
arint8 |
object (Array of number) |
ARRAY OF SINT |
aruint8 |
object (Array of number) |
ARRAY OF USINT, ARRAY OF BYTE |
arint16 |
object (Array of number) |
ARRAY OF INT |
aruint16 |
object (Array of number) |
ARRAY OF UINT, ARRAY OF WORD |
arint32 |
object (Array of number) |
ARRAY OF DINT |
aruint32 |
object (Array of number) |
ARRAY OF UDINT, ARRAY OF DWORD |
arint64 |
object (Array of BigInt) |
ARRAY OF LINT |
aruint64 |
object (Array of BigInt) |
ARRAY OF ULINT, ARRAY OF LWORD |
arfloat |
object (Array of number) |
ARRAY OF REAL |
ardouble |
object (Array of number) |
ARRAY OF LREAL |
arstring |
object (Array of string) |
ARRAY OF STRING |
object |
object |
via library |
The first column is the datatype which is used for the attribute type in the msg.payload when reading or writing Data Layer Requests with the property of the payload format set to value + type (json).
For example, a READ request to the path framework/metrics/system/cpu-utilisation-percent might return the following json in msg.payload:
{
"value": 17.5,
"type": "double"
}