The ADS Interface

The functions adsRead(), adsReadFloat(), adsReadDouble(), adsWrite(), adsWriteFloat() and adsWriteDouble() implement the ADS/AMS interface of Beckhoff (www.beckhoff.de).

$ret = adsRead( $host, $AMSPort, $indexGroup, $indexOffset, $length);
$ret = adsWrite( $host, $AMSPort, $indexGroup, $indexOffset, $length, $data);
$ret = adsReadFloat( $host, $AMSPort, $indexGroup, $indexOffset, 4);
$ret = adsWriteFloat( $host, $AMSPort, $indexGroup, $indexOffset, 4, $xdata);
$ret = adsReadDouble( $host, $AMSPort, $indexGroup, $indexOffset, 8);
$ret = adsWriteDouble( $host, $AMSPort, $indexGroup, $indexOffset, 8, $xdata);

$ret = adsRead( "hasc1", 801, 0xf020, 0x59, 4)
$ret = adsWrite( "131.169.123.123", 801, 0xf020, 0x59, 4, 0x3f800000)

The $AMSPort is 801 for the 'SPS Laufzeitsystem 1', for example.

$indexGroup and $indexOffset identify the register.

$length can be 1, 2, or 4 for int I/O or 4 for float I/O.

Note: Before a client can connect to a TwinCAD system via ADS, the corresponding host has to be authorized on the server by name, AMS Net Id ( e.g.: 131.169.123.123.1.1) and address. The TwinCAD system has to be re-started after a new host has been authorized. TwinCAD runs on Windows PCs. The wirewall of this PC has to be disabled. ADS uses the TCP/IP port 48808.

Note: Before a client can connect to a CX system a static route has to be added on the CX. You have a TwinCat running on a Windows PC and use 'Zielsystem waehlen' to select the CX. Then restart the CX, enter Config mode, double-click Routing Einstellungen, add a static route and make sure the remote route is static (login information will be prompted).