From b0795a21310ec04a05b96736b5e9c11e698c77ee Mon Sep 17 00:00:00 2001
From: Bernhard Kirchen <schlimmchen@posteo.net>
Date: Thu, 7 Mar 2024 21:15:43 +0100
Subject: [PATCH] DPL limit scaling: only for supported models

---
 src/PowerLimiter.cpp | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/PowerLimiter.cpp b/src/PowerLimiter.cpp
index 32fa9762d..ec3542ad7 100644
--- a/src/PowerLimiter.cpp
+++ b/src/PowerLimiter.cpp
@@ -12,6 +12,7 @@
 #include "Huawei_can.h"
 #include <VictronMppt.h>
 #include "MessageOutput.h"
+#include "inverters/HMS_4CH.h"
 #include <ctime>
 #include <cmath>
 #include <frozen/map.h>
@@ -634,6 +635,14 @@ static int32_t scalePowerLimit(std::shared_ptr<InverterAbstract> inverter, int32
     std::list<ChannelNum_t> dcChnls = inverter->Statistics()->getChannelsByType(TYPE_DC);
     size_t dcTotalChnls = dcChnls.size();
 
+    // according to the upstream projects README (table with supported devs),
+    // every 2 channel inverter has 2 MPPTs. then there are the HM*S* 4 channel
+    // models which have 4 MPPTs. all others have a different number of MPPTs
+    // than inputs. those are not supported by the current scaling mechanism.
+    bool supported = dcTotalChnls == 2;
+    supported |= dcTotalChnls == 4 && HMS_4CH::isValidSerial(inverter->serial());
+    if (!supported) { return newLimit; }
+
     // test for a reasonable power limit that allows us to assume that an input
     // channel with little energy is actually not producing, rather than
     // producing very little due to the very low limit.