door). Additionally, two LED indicators are provided for each I/O station in a D-frame in 
order to indicate if the I/O station is empty or full and if the I/O station door is locked or 
unlocked. This plant feature reduces the frame storage slot capacity by 160 for a Model D23 
and by 176 for a Model D53. The I/O stations increase the maximum library I/O slot 
capacity from 32 to 224. The multiple I/O stations can double the maximum insert and eject 
throughput since both accessors can be used. The D23 and D53 models remain compatible 
with existing Models L22, L32, L52, D22, D32, and D52.
The models of the TS3500 Tape Library vary depending on the type of media they contain 
and whether the frame is a service bay, a base frame, or an expansion frame. Table 1 lists 
each frame and its characteristics.
Table 1. TS3500 Tape Library frame models
Frame 
model Type Depth
Media type and 
capacity Other
HA1
Service Bay 
A
Short N/A N/A
• Required when an 
optional second accessor 
is ordered
• Contains slots for 
diagnostic cartridges only
L22 Base frame Short 3592
Up to 12 
drives and 
up to 260 
cartridges
• May require L23 model 
conversion OR 
installation of FC 1700
1
L23 Base frame Short 3592
Up to 12 
drives and 
up to 260 
cartridges
• Equipped with the 
enhanced frame control 
assembly
• Optionally equipped 
with TS7700 backend 
switches
D22
Expansion 
frame
Short 3592
Up to 12 
drives and 
up to 400 
cartridges
• Optionally configured 
as service bay B
• May require D23 model 
conversion OR 
installation of FC 1701
1
D23 Expansion 
frame
Short 3592 Up to 12 
drives and 
• Optionally equipped