From f7c11febe526659d4322b2b8c6b72671b33b86b2 Mon Sep 17 00:00:00 2001
From: Mikayla Fischler <mikayla@ky8.io>
Date: Fri, 22 Apr 2022 10:21:15 -0400
Subject: [PATCH] check if interface exists before trying to get its device or
 type

---
 reactor-plc/startup.lua | 2 +-
 rtu/startup.lua         | 2 +-
 scada-common/ppm.lua    | 8 ++++++--
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/reactor-plc/startup.lua b/reactor-plc/startup.lua
index 1737f3f..b57845c 100644
--- a/reactor-plc/startup.lua
+++ b/reactor-plc/startup.lua
@@ -10,7 +10,7 @@ os.loadAPI("scada-common/comms.lua")
 os.loadAPI("config.lua")
 os.loadAPI("plc.lua")
 
-local R_PLC_VERSION = "alpha-v0.2.2"
+local R_PLC_VERSION = "alpha-v0.2.3"
 
 local print = util.print
 local println = util.println
diff --git a/rtu/startup.lua b/rtu/startup.lua
index bb7e3e1..0074625 100644
--- a/rtu/startup.lua
+++ b/rtu/startup.lua
@@ -17,7 +17,7 @@ os.loadAPI("dev/boiler_rtu.lua")
 os.loadAPI("dev/imatrix_rtu.lua")
 os.loadAPI("dev/turbine_rtu.lua")
 
-local RTU_VERSION = "alpha-v0.2.1"
+local RTU_VERSION = "alpha-v0.2.2"
 
 local print = util.print
 local println = util.println
diff --git a/scada-common/ppm.lua b/scada-common/ppm.lua
index fd92b23..f751342 100644
--- a/scada-common/ppm.lua
+++ b/scada-common/ppm.lua
@@ -174,12 +174,16 @@ end
 
 -- get a mounted peripheral by side/interface
 function get_periph(iface)
-    return self.mounts[iface].dev
+    if self.mounts[iface] then
+        return self.mounts[iface].dev
+    else return nil end
 end
 
 -- get a mounted peripheral type by side/interface
 function get_type(iface)
-    return self.mounts[iface].type
+    if self.mounts[iface] then
+        return self.mounts[iface].type
+    else return nil end
 end
 
 -- get all mounted peripherals by type