From e775e1a5b9fb110a2be136d1eb4e85d66f8c2cee Mon Sep 17 00:00:00 2001
From: Jeffrey_Li <412100639@qq.com>
Date: Mon, 12 Jun 2023 00:08:17 +0800
Subject: [PATCH] =?UTF-8?q?=E8=A1=A5=E5=85=85=E6=BC=8F=E4=BC=A0=E6=96=87?=
 =?UTF-8?q?=E4=BB=B6?=
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---
 Cigarette/PLC/PLCDevice.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/Cigarette/PLC/PLCDevice.cpp b/Cigarette/PLC/PLCDevice.cpp
index 661f147..20d95aa 100644
--- a/Cigarette/PLC/PLCDevice.cpp
+++ b/Cigarette/PLC/PLCDevice.cpp
@@ -7,7 +7,7 @@
 
 extern SysConf g_sys_conf;
 
-modbus_t * g_modbus;		//Modbus TCP
+modbus_t * g_modbus = NULL;		//Modbus TCP
 
 bool PLCDevice::init_plc(PLCDevice* PLCptr)
 {
@@ -29,8 +29,11 @@ bool PLCDevice::init_plc(PLCDevice* PLCptr)
 }
 bool PLCDevice::disconnect_plc(void)
 {
-	modbus_close(g_modbus);
-	modbus_free(g_modbus);
+	if(g_modbus)
+	{
+		modbus_close(g_modbus);
+		modbus_free(g_modbus);
+	}
 	return true;
 }
 int PLCDevice::write_bit_2_plc(int addr, int value)