Multichannel Systems STG4004+STG4008 Manual - Manual (Page 87)

Analog Output Signals
83
Example 3a: Current Mode: The red trace shows the current output (+I) with a load resistance
of 100 k
; and the pink trace shows the TTL output from the Sync Out that was used for
triggering the oscilloscope

Rise time with programmed 5 V and 500 μA pulses, 100 k
 load resistance.
Rise time (10 % / 90 %) = 12 μs