diff --git a/ohmpi/hardware_components/mux_2024_rev_0_0.py b/ohmpi/hardware_components/mux_2024_rev_0_0.py
index 71c0655ec9e291b8add94d284caea33c30cb257c..470c3c1c9db79272a131f89d13222a126971f4a9 100644
--- a/ohmpi/hardware_components/mux_2024_rev_0_0.py
+++ b/ohmpi/hardware_components/mux_2024_rev_0_0.py
@@ -12,7 +12,7 @@ MUX_CONFIG.update({'voltage_max': 50., 'current_max': 3.})  # board default valu
 MUX_CONFIG.update({'activation_delay': 0.01, 'release_delay': 0.005})  # s
 # defaults to 4 roles cabling electrodes from 1 to 8
 default_mux_cabling = {(elec, role) : ('mux_1', elec) for role in ['A', 'B', 'M', 'N'] for elec in range(1,9)}
-# defaults to ic connection
+# defaults to i2c connection
 ctl_connection = HARDWARE_CONFIG['ctl'].pop('connection', 'i2c')
 
 inner_cabling = {'4_roles' : {(1, 'X'): {'MCP': 0, 'MCP_GPIO': 0}, (1, 'Y'): {'MCP': 0, 'MCP_GPIO': 8},
diff --git a/ohmpi/hardware_system.py b/ohmpi/hardware_system.py
index 5427a16bee114189f4fdbb2a7e2ca705305e0085..3ee3e0233392cd5dec153e73901e997e901f8128 100644
--- a/ohmpi/hardware_system.py
+++ b/ohmpi/hardware_system.py
@@ -328,7 +328,7 @@ class OhmPiHardware:
         ax[3].plot(self.readings[v, 0], (self.readings[v, 2] * (self.readings[v, 4] - self.sp)) / self.readings[v, 3],
                    '-m', marker='.', label='R [ohm]')
         ax[3].set_ylabel('R [ohm]')
-        ax[4].plot(self.readings[v, 0], np.ones_like(self.readings[v,0]) * self.sp, '-o', marker='.', label='SP [mV]')
+        ax[4].plot(self.readings[v, 0], np.ones_like(self.readings[v,0]) * self.sp, '-k', marker='.', label='SP [mV]')
         ax[4].set_ylabel('SP [mV]')
         fig.legend()
         if save_fig: