Real as in not PWM 
Like I said, ATmega based have no 0-5V (aka DAC) output although analogWrite() suggests it. analogWrite() is PWM (Google it ;)).
That E908A001 expects real 0-10V. It doesnn't specify the current but it's a control signal so it's probably low. Increase PWM frequency, add amplification (transistor like above or opamp etc) and a RC filter
I used 3kHz PWM, an opamp* with gain 2x and an RC filter (1k and 100nF if I recall correctly) on the input of the opamp.
Btw, it's a bit ironic. The E908A001 will translate the 0-10V to PWM again :
*Remember you need more supply voltage then the max desirable output voltage. The opamp can only reach like 90% (see datasheet) of it's supply voltage. Aka 12V supply if you want 10V out. OR you can use a rail-to-rail opamp.