From e136709cac59ceb1d9d2758c32faadb6469b5108 Mon Sep 17 00:00:00 2001
From: Robert Jordens <jordens@gmail.com>
Date: Thu, 31 May 2018 16:36:53 +0000
Subject: [PATCH] suservo: document gain state

close #1030
---
 artiq/coredevice/suservo.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/artiq/coredevice/suservo.py b/artiq/coredevice/suservo.py
index 578cf7bd3..0e5811163 100644
--- a/artiq/coredevice/suservo.py
+++ b/artiq/coredevice/suservo.py
@@ -199,6 +199,10 @@ class SUServo:
 
         This method does not advance the timeline but consumes all slack.
 
+        The PGIA gain setting must be known prior to using this method, either
+        by setting the gain (:meth:`set_pgia_mu`) or by supplying it
+        (:attr:`gains` or via the constructor/device database).
+
         :param adc: ADC channel number (0-7)
         :return: ADC voltage
         """