The Columbus V-900 logger requires a MicroCard formatted using the MS-DOS FAT16 format. The Diskutil application, however, does not allow to specify this format.
The task can be achieved using the CLI, however.
Quoting from Spotwise.
List the devices available (to ensure we format the right one):
$ diskutil list
If the disk is less than 2G, type:
$ diskutil partitiondisk /dev/disk1 1 MBRFormat "MS-DOS FAT16" "Data" 512M
If the disk is more than 2G, first partition the disk in partitions of 2G max (you can use DiskUtil’s GUI) and then erase the volumes with the following commands:
$ diskutil eraseVolume "MS-DOS FAT16" COL1 /dev/disk3s1 $ diskutil eraseVolume "MS-DOS FAT16" COL2 /dev/disk3s2
Remark Microsoft MS-DOS versions 4.0 and later allow FDISK to partition hard disks up to 4 gigabytes (GB) in size. However, the MS-DOS file allocation table (FAT) file system can support only 2 GB per partition. Because of this fact, a hard disk between 2 and 4 GB in size must be broken down into multiple partitions, each of which does not exceed 2 GB. (Source http://support.microsoft.com/kb/118335)