improvement for syrlinks code

CHANGELOG.md

@@ -15,6 +15,10 @@ list yields a list of all related PRs for each release.
 - COM `Submode` enum moved from subsystem module to separate definitions module and renamed
   to `Mode`. Added re-imports with the name `ComMode` in the subsystem and syrlinks module.
 
+## Fixed
+
+- Eb to N0 calculation: Improve robustness against division by zero.
+
 # [v2.19.4] 2023-03-24
 
 ## Fixed

eive_tmtc/tmtc/com/syrlinks_handler.py

@@ -304,7 +304,11 @@ def handle_syrlinks_rx_registers_dataset(printer: FsfwTmTcPrinter, hk_data: byte
     rx_agc = rx_agc_value & 0xFFF
     rx_demod_eb = struct.unpack("!I", hk_data[13:17])[0] & 0xFFFFFF
     rx_demod_n0 = struct.unpack("!I", hk_data[17:21])[0] & 0xFFFFFF
+    if rx_demod_n0 > 0:
         eb_to_n0 = 20 * math.log10(rx_demod_eb / rx_demod_n0) - 3
+    else:
+        logging.getLogger(__name__).warning("RX Demod N0 is 0, can not calculate Eb to N0")
+        eb_to_n0 = 0
     rx_data_rate_raw = hk_data[21]
     rx_data_rate = -1
     if rx_data_rate_raw == 0: