Synology DiskStation User's Guide
Based on DSM 3.1
225 Appendix A: Synology DiskStation Specifications
Limitations
Each Synology DiskStation supports up to 2 USB printers.
USBCopy function supports USB disks with FAT32 and NTFS file system.
Some digital cameras are defined as a Still Image Device, such as Canon. For such devices,
Synology DiskStation only supports USBCopy function (No USB share function).
For Mac users, Synology DiskStation only supports USB printers with PostScript.