diff --git a/rtu/startup.lua b/rtu/startup.lua
index 209fed6..ed39c9a 100644
--- a/rtu/startup.lua
+++ b/rtu/startup.lua
@@ -25,7 +25,7 @@ local imatrix_rtu       = require("rtu.dev.imatrix_rtu")
 local turbine_rtu       = require("rtu.dev.turbine_rtu")
 local turbinev_rtu      = require("rtu.dev.turbinev_rtu")
 
-local RTU_VERSION = "beta-v0.7.8"
+local RTU_VERSION = "beta-v0.7.9"
 
 local rtu_t = types.rtu_t
 
@@ -121,7 +121,7 @@ local function configure()
         local io_reactor = rtu_redstone[entry_idx].for_reactor
 
         -- CHECK: reactor ID must be >= to 1
-        if type(io_reactor) ~= "number" or io_reactor <= 0 or io_reactor ~= math.floor(io_reactor) then
+        if (not util.is_int(io_reactor)) or (io_reactor <= 0) then
             println(util.c("configure> redstone entry #", entry_idx, " : ", io_reactor, " isn't an integer >= 1"))
             return false
         end
@@ -244,13 +244,13 @@ local function configure()
         end
 
         -- CHECK: index is an integer >= 1
-        if type(index) ~= "number" or index <= 0 or index ~= math.floor(index) then
+        if (not util.is_int(index)) or (index <= 0) then
             println(util.c("configure> device entry #", i, ": index ", index, " isn't an integer >= 1"))
             return false
         end
 
         -- CHECK: reactor is an integer >= 1
-        if type(for_reactor) ~= "number" or for_reactor <= 0 or for_reactor ~= math.floor(for_reactor) then
+        if (not util.is_int(for_reactor)) or (for_reactor <= 0) then
             println(util.c("configure> device entry #", i, ": reactor ", for_reactor, " isn't an integer >= 1"))
             return false
         end
diff --git a/scada-common/rsio.lua b/scada-common/rsio.lua
index 05f078c..04ab23c 100644
--- a/scada-common/rsio.lua
+++ b/scada-common/rsio.lua
@@ -2,6 +2,8 @@
 -- Redstone I/O
 --
 
+local util = require("scada-common.util")
+
 local rsio = {}
 
 ----------------------
@@ -101,7 +103,7 @@ function rsio.to_string(channel)
         "R_PLC_TIMEOUT"
     }
 
-    if type(channel) == "number" and channel > 0 and channel <= #names then
+    if util.is_int(channel) and channel > 0 and channel <= #names then
         return names[channel]
     else
         return ""
@@ -184,7 +186,7 @@ function rsio.get_io_mode(channel)
         IO_MODE.DIGITAL_OUT     -- R_PLC_TIMEOUT
     }
 
-    if type(channel) == "number" and channel > 0 and channel <= #modes then
+    if util.is_int(channel) and channel > 0 and channel <= #modes then
         return modes[channel]
     else
         return IO_MODE.ANALOG_IN
@@ -201,7 +203,7 @@ local RS_SIDES = rs.getSides()
 ---@param channel RS_IO
 ---@return boolean valid
 function rsio.is_valid_channel(channel)
-    return (type(channel) == "number") and (channel > 0) and (channel <= RS_IO.R_PLC_TIMEOUT)
+    return util.is_int(channel) and (channel > 0) and (channel <= RS_IO.R_PLC_TIMEOUT)
 end
 
 -- check if a side is valid
@@ -220,7 +222,7 @@ end
 ---@param color integer
 ---@return boolean valid
 function rsio.is_color(color)
-    return (type(color) == "number") and (color > 0) and (_B_AND(color, (color - 1)) == 0);
+    return util.is_int(color) and (color > 0) and (_B_AND(color, (color - 1)) == 0);
 end
 
 -----------------
@@ -243,7 +245,7 @@ end
 ---@param level IO_LVL
 ---@return boolean
 function rsio.digital_write(channel, level)
-    if type(channel) ~= "number" or channel < RS_IO.F_ALARM or channel > RS_IO.R_PLC_TIMEOUT then
+    if (not util.is_int(channel)) or (channel < RS_IO.F_ALARM) or (channel > RS_IO.R_PLC_TIMEOUT) then
         return false
     else
         return RS_DIO_MAP[channel]._f(level)
@@ -255,7 +257,7 @@ end
 ---@param level IO_LVL
 ---@return boolean
 function rsio.digital_is_active(channel, level)
-    if type(channel) ~= "number" or channel > RS_IO.R_ENABLE then
+    if (not util.is_int(channel)) or (channel > RS_IO.R_ENABLE) then
         return false
     else
         return RS_DIO_MAP[channel]._f(level)
diff --git a/scada-common/util.lua b/scada-common/util.lua
index ba417ff..c155922 100644
--- a/scada-common/util.lua
+++ b/scada-common/util.lua
@@ -79,6 +79,13 @@ end
 
 -- MATH --
 
+-- is a value an integer
+---@param x any value
+---@return boolean if the number is an integer
+function util.is_int(x)
+    return type(x) == "number" and x == math.floor(x)
+end
+
 -- round a number to an integer
 ---@return integer rounded
 function util.round(x)