The gain settings when an external signal is input to EXT SIG IN to be used as an amplifier are as follows:
20 V model: CV -20.00 V/V to +20.00 V/V, CC -20.00 A/V to +20.00 A/V
40 V model: CV -40.0 V/V to +40.0 V/V, CC -10.00 A/V to +10.00 A/V
60 V model: CV -60.0 V/V to +60.0 V/V, CC -6.70 A/V to +6.70 A/V
80 V model: CV -80.0 V/V to +80.0 V/V, CC -5.00 A/V to +5.00 A/V
For the details, read the user’s manual – chapter of Using the EXT SIG IN Signal.


