Bind etherlab process and use it directly in node.
Etherlab must be installed first. To install etherlab, you can follow the instruction from etherlab repository
This package needs the etherlab shared library and header to be installed in /usr/local/.
If etherlab is installed in different location, i.e. /opt/etherlab, then you can create symlink to /usr/local/
ln -s /opt/etherlab/lib/libethercat.so /usr/local/lib/libethercat.so
ln -s /opt/etherlab/include/ecrt.h /usr/local/include/ecrt.hHow to create slave json configuration
Each slave is configured via json file. For example, if a master has 1 Beckhoff EL2008 slave attached, then the configuration would look like this
[
{
"alias":0,
"position":0,
"vendor_id":"0x00000002",
"product_code":"0x07d83052",
"syncs":[
{
"index":2,
"watchdog_enabled":false,
"pdos":[
{
"index":"0x1600",
"entries":[
{
"index":"0x7000",
"subindex":"0x01",
"size":1,
"add_to_domain":true,
"swap_endian":false,
"signed":false
}
]
},
{
"index":"0x1601",
"entries":[
{
"index":"0x7010",
"subindex":"0x01",
"size":1,
"add_to_domain":true,
"swap_endian":false,
"signed":false
}
]
},
{
"index":"0x1602",
"entries":[
{
"index":"0x7020",
"subindex":"0x01",
"size":1,
"add_to_domain":true,
"swap_endian":false,
"signed":false
}
]
},
{
"index":"0x1603",
"entries":[
{
"index":"0x7030",
"subindex":"0x01",
"size":1,
"add_to_domain":true,
"swap_endian":false,
"signed":false
}
]
},
{
"index":"0x1604",
"entries":[
{
"index":"0x7040",
"subindex":"0x01",
"size":1,
"add_to_domain":true,
"swap_endian":false,
"signed":false
}
]
},
{
"index":"0x1605",
"entries":[
{
"index":"0x7050",
"subindex":"0x01",
"size":1,
"add_to_domain":true,
"swap_endian":false,
"signed":false
}
]
},
{
"index":"0x1606",
"entries":[
{
"index":"0x7060",
"subindex":"0x01",
"size":1,
"add_to_domain":true,
"swap_endian":false,
"signed":false
}
]
},
{
"index":"0x1607",
"entries":[
{
"index":"0x7070",
"subindex":"0x01",
"size":1,
"add_to_domain":true,
"swap_endian":false,
"signed":false
}
]
}
]
}
]
}
]const __etherlab = require('etherlab-nodejs');
const config = './slaves.json';
const frequency = 5000; // in hertz
const etherlab = new __etherlab(config, frequency);
etherlab.on('data', (data, latency) => {
console.log(data, latency);
console.log(etherlab.getLatencyAndJitter());
});
etherlab.on('state', current => {
console.log('master\'s current state ', current);
});
etherlab.on('ready', async () => {
const domain = await etherlab.getDomain();
console.log(domain);
});
etherlab.on('error', error => {
console.error(error);
});
etherlab.start();