diff --git a/ad9959/src/lib.rs b/ad9959/src/lib.rs
index 206d90a..21dfa21 100644
--- a/ad9959/src/lib.rs
+++ b/ad9959/src/lib.rs
@@ -558,13 +558,15 @@ impl ProfileSerializer {
     /// * `channels` - A list of channels to apply the configuration to.
     /// * `ftw` - If provided, indicates a frequency tuning word for the channels.
     /// * `pow` - If provided, indicates a phase offset word for the channels.
-    /// * `acr` - If provided, indicates the amplitude control register for the channels.
+    /// * `acr` - If provided, indicates the amplitude control register for the channels. The ACR
+    ///   should be stored in the 3 LSB of the word. Note that if amplitude scaling is to be used,
+    ///   the "Amplitude multiplier enable" bit must be set.
     pub fn update_channels(
         &mut self,
         channels: &[Channel],
         ftw: Option<u32>,
         pow: Option<u16>,
-        acr: Option<u16>,
+        acr: Option<u32>,
     ) {
         let mut csr: u8 = *0u8.set_bits(1..3, self.mode as u8);
         for channel in channels.iter() {
@@ -582,7 +584,7 @@ impl ProfileSerializer {
         }
 
         if let Some(acr) = acr {
-            self.add_write(Register::ACR, &acr.to_be_bytes());
+            self.add_write(Register::ACR, &acr.to_be_bytes()[1..=3]);
         }
     }
 
@@ -606,14 +608,14 @@ impl ProfileSerializer {
         // Pad the buffer to 32-bit alignment by adding dummy writes to CSR and LSRR.
         let padding = 4 - (self.index % 4);
         match padding {
-            0 => {}
             1 => {
                 // For a pad size of 1, we have to pad with 5 bytes to align things.
                 self.add_write(Register::CSR, &[(self.mode as u8) << 1]);
-                self.add_write(Register::LSRR, &[0, 0, 0]);
+                self.add_write(Register::LSRR, &[0, 0]);
             }
             2 => self.add_write(Register::CSR, &[(self.mode as u8) << 1]),
-            3 => self.add_write(Register::LSRR, &[0, 0, 0]),
+            3 => self.add_write(Register::LSRR, &[0, 0]),
+            4 => {}
 
             _ => unreachable!(),
         }
diff --git a/hitl/run.sh b/hitl/run.sh
index a01a472..8fe9a3a 100755
--- a/hitl/run.sh
+++ b/hitl/run.sh
@@ -22,4 +22,6 @@ python3 -m pip install -r requirements.txt
 ping -c 5 -w 20 stabilizer-hitl
 
 # Test the MQTT interface.
-python3 miniconf.py dt/sinara/stabilizer afe/0 '"G2"'
+python3 miniconf.py dt/sinara/stabilizer afe/0='"G2"'
+python3 miniconf.py dt/sinara/stabilizer afe/0='"G1"' iir_ch/0/0=\
+'{"y_min": -32767, "y_max": 32767, "y_offset": 0, "ba": [1.0, 0, 0, 0, 0]}'
diff --git a/miniconf.py b/miniconf.py
index 019ebcb..b059f78 100644
--- a/miniconf.py
+++ b/miniconf.py
@@ -83,19 +83,19 @@ class Miniconf:
 def main():
     parser = argparse.ArgumentParser(
             description='Miniconf command line interface.',
-            epilog='''Example:
-            %(prog)s -v -b mqtt dt/sinara/stabilizer afe/0 '"G10"'
-            ''')
+            formatter_class=argparse.RawDescriptionHelpFormatter,
+            epilog='''Examples:
+%(prog)s dt/sinara/stabilizer afe/0='"G2"' iir_ch/0/0=\
+'{"y_min": -32767, "y_max": 32767, "y_offset": 0, "ba": [1.0, 0, 0, 0, 0]}'
+''')
     parser.add_argument('-v', '--verbose', action='count', default=0,
                         help='Increase logging verbosity')
     parser.add_argument('--broker', '-b', default='mqtt', type=str,
                         help='The MQTT broker address')
     parser.add_argument('prefix', type=str,
                         help='The MQTT topic prefix of the target')
-    parser.add_argument('path', type=str,
-                        help='The setting path to configure')
-    parser.add_argument('value', type=str,
-                        help='The value of setting in JSON format')
+    parser.add_argument('settings', metavar="KEY=VALUE", nargs='+',
+                        help='JSON encoded values for settings path keys.')
 
     args = parser.parse_args()
 
@@ -107,8 +107,10 @@ def main():
 
     async def configure_settings():
         interface = await Miniconf.create(args.prefix, args.broker)
-        response = await interface.command(args.path, json.loads(args.value))
-        print(f"Response: {response}")
+        for kv in args.settings:
+            path, value = kv.split("=", 1)
+            response = await interface.command(path, json.loads(value))
+            print(response)
 
     loop.run_until_complete(configure_settings())
 
diff --git a/src/hardware/pounder/dds_output.rs b/src/hardware/pounder/dds_output.rs
index c7c5e6d..e755482 100644
--- a/src/hardware/pounder/dds_output.rs
+++ b/src/hardware/pounder/dds_output.rs
@@ -144,14 +144,15 @@ impl<'a> ProfileBuilder<'a> {
     /// * `channels` - A list of channels to apply the configuration to.
     /// * `ftw` - If provided, indicates a frequency tuning word for the channels.
     /// * `pow` - If provided, indicates a phase offset word for the channels.
-    /// * `acr` - If provided, indicates the amplitude control register for the channels.
+    /// * `acr` - If provided, indicates the amplitude control register for the channels. The
+    ///   24-bits of the ACR should be stored in the last 3 LSB.
     #[allow(dead_code)]
     pub fn update_channels(
         mut self,
         channels: &[Channel],
         ftw: Option<u32>,
         pow: Option<u16>,
-        acr: Option<u16>,
+        acr: Option<u32>,
     ) -> Self {
         self.serializer.update_channels(channels, ftw, pow, acr);
         self