OKThe link calls it an SSR, but its datasheet has it as a proportional controller.So, it's different.
I wonder if a PWM'ed 0/10V would suffice or if it requires a nice, smooth, 'constant' (within range) DC control voltage.
It'd be easy enough to switch (PWM) a transistor, and therefore the controller's input, between 0 and 10V, especially since it's just LED current there.Smoothing the Arduino PWM (approx 430Hz ?) with a low-pass filter and an op-amp and then amplifying the result (X2) would be more complicated, but hardly impossible.
OK.Attached is a drawing for the first (easiest) option.The transistor is just a "garden variety" NPN.*** "Ordinary" SSRs need a load on the output - without a load the output will always show high-voltage (assuming use of a modern DVM) regardless the control state. ***