From a1571dcacd0d238f4884dbc227b025760f9fe0c4 Mon Sep 17 00:00:00 2001
From: devStorm <59678453+developStorm@users.noreply.github.com>
Date: Tue, 23 Apr 2024 21:43:31 -0700
Subject: [PATCH] patch: getVersionNumber function

to construct version number with major, minor, and patch from each individual bytes in Ausbg fields
---
 modules/siemens/s7.go | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/modules/siemens/s7.go b/modules/siemens/s7.go
index d0b8b011..a08194c4 100644
--- a/modules/siemens/s7.go
+++ b/modules/siemens/s7.go
@@ -295,8 +295,13 @@ func parseModuleIDDataRecord(data []byte) (*moduleIDData, error) {
 
 // Constructs the version number from a moduleIDData record.
 func getVersionNumber(record *moduleIDData) string {
-	lastByteAusbg1 := record.Ausbg1 & 0xFF
-	return fmt.Sprintf("V%d.%d", lastByteAusbg1, record.Ausbg2)
+	// The major, minor, and patch versions are stored in the lower 8 bits of Ausbg1,
+	// the upper 8 bits of Ausbg2, and the lower 8 bits of Ausbg2, respectively.
+	major := record.Ausbg1 & 0xFF
+	minor := record.Ausbg2 >> 8
+	patch := record.Ausbg2 & 0xFF
+
+	return fmt.Sprintf("%d.%d.%d", major, minor, patch)
 }
 
 func parseModuleIdentificationRequest(logStruct *S7Log, s7Packet *S7Packet) error {