Booking back is only necessary when you replace the CPU or download your program to another CPU...

The PO objects are available in the ALM (Automatic License Manager) on the ES. The PO needed will be taken from the total available. PO is available in several quantities-> 100, 500, 1000 etc.

The PO will be downloaded to the CPU. If you have another program on the same ES, but with less PO, the amount not needed will be booked back.

Hi,

this happens when you have not enogh "empty licences"...Simple issue, hard to explain...I will try...

Let's assume the following:

You have 5 licenses of 100 PO each what is in total 500 PO. You have a program wich needs 250 PO. When downloading the program the first time 250 PO are deducted from the available PO licenses. So 2 licenses will have a count of '0' and a third license wil have count of 50. When adding something to your software what in e.g. needs one PO by "changes only" the counter will decreased by one PO. So the count of the third license will be '49' after download. When deleting parts of software the corresponding amout of PO will be booked back, means the counter will increase. I guess up to here everything is clear.

And now comes the point: The counter of a license can not increase higher than it's initial value. With other words; A 100 PO license can not count higher (by booking back POs) than 100. And this is what your message wants to tell you. There is no license whose counter could be increased, but it should be.

There a few reasons why this can happen.Examples:

The program was loaded from an other engineering station (entire or changes). The necessary PO where booked from that station. The empty license (or partly empty licenses) where not transfered from that station to the current station. Remedy: transfer the empty license (or partly empty licenses) to the current station.

The same can occur when working with 2 engineering stations via network. Remedy: Maintain the PO license only on one station (e.g. station 1). When downloading changes from the 2nd one and new POs are required or should be booked back, a hint will apear in the download log that "X POs should be booked" or "booked back but couldn't". With the next download (e.g. changes only) from the station with the PO licenses, the counters of the licenses will be adjusted including the "depts" or "deposits" created when downloading from the station without PO licenses. This is not avoiding the message during download on station 2, but it helps to keep an overwiev about booked and available PO licences. Also, you get that message only on station 2 and you know why.

An other reason my be restoring a backup of a system partition and the backup file was created incl. PO licenses. Remedy: Maintain a seperate partition for licenses on your station, so a backup-restore scenario of the system partition won't affect your licenses.

Best regards...