User manual

Page 56 915U-2 Wireless I/O
Page 56 User Manual
If after 600 seconds, the module still has not received an update from the other module,
register 30501 will be set to the “Fail Value” (in this case 0).
If the “Invalidate on Fail” were ticked, the value would be set to a null or invalidated
value (~).
If this register was mapped to some other location the mapping would be inhibited until
the” Invalid” value was updated with a real value.
The maximum number of Fail Safe blocks you can have is 50.
“Invalid” register state
Figure 33- Invalid Register State
All registers within the module can have various states depending on what type of
register it is and what sort of value it holds, a typical analog range is between 0 and
65535 and a digital can be 0 or 1.
All registers that are not associated with any physical I/O have another state which we
call “invalid”, this state means that the value has not been written to and so does not
hold a value but more a non value or null.
If you were to read the registers using the “I/O Diagnostics” an invalid register would
read “~“as shown in Figure 33 above.
Any mapping with an invalid register will be inhibited from sending. This
is to ensure the data that gets to the destination is valid and not just
default values that the module starts up with. Refer to section 4.2.7
“Failsafe Blocks” above for a way of configuring a registers with a valid
value at start-up
4.2.8 Sensitivity Blocks
All registers have a configurable “Sensitivity” value, which determines how much the
register needs to change by before being sent as a “Change of State” (COS).
All registers have a default sensitivity value of 1 except the following.
The 12 analog inputs have a sensitivity of 1000 (3.2%) and the 24 floating point values
will have a default sensitivity of 0.5 units. In the case of 38001 – 38004 this will be
0.5mA, in the case of 38005-38012 it will be Volts and in 38013 – 38016 it will be Hertz.