Toshiba XLTR-200 사용자 설명서

다운로드
페이지 99
 
  
48
13.2  Metasys N2 
• 
The gateway acts as a Johnson Controls Metasys N2 slave, and supports 
N2 analog input, analog output, binary input and binary output object types. 
 
• 
Analog input (AI) objects are used for monitoring analog status items.  AI 
objects support low alarm limits, low warning limits, high warning limits, 
high alarm limits and differential values.  Change of state (COS), alarm and 
warning functions can also be enabled.  An AI object will accept an 
override command, but will not change its actual value or indicate override 
active.  A “multiplier value” is associated with the object, and is multiplied 
to the point’s value to produce the floating-point AI value sent to the NCU 
(AI value = [point data value] X multiplier).  
 
• 
Analog output (AO) objects are used for setting and monitoring analog 
control and configuration items.  An AO value can be modified by issuing 
an override command.  Issuing a release command will not cause the AO 
to automatically return to its pre-override value, nor will the AO 
automatically return to its pre-override value after a certain time period of 
no communication.  A “multiplier value” is associated with the object, and 
the floating-point AO value is divided by this multiplier to produce the result 
that is passed on to a point’s value (point data value = [AO value] / 
multiplier).  
 
• 
Binary input (BI) objects are used for monitoring discrete (digital) status 
items.  BI objects support COS, alarm enabling and normal/alarm status 
indications.  A BI object will accept an override command, but will not 
change its actual value or indicate override active.  A “bit mask” is 
associated with the object, and is used to determine the current state of the 
BI by inspecting the point’s data at the bit location(s) indicated in the bit 
mask.  If all of the bit locations of the point’s data value indicated by a “1” in 
the bit mask are set, then the BI’s current state is set to “1”.  Else, it is set 
to “0”.  The point data’s least-significant bit (LSB) is bit #0, and the most-
significant bit (MSB) is bit #15. 
 
• 
Binary output (BO) points are used for setting and monitoring discrete 
control and configuration items.  A BO value can be modified by issuing an 
override command.  Issuing a release command will not cause the BO to 
automatically return to its pre-override value, nor will the BO return to its 
pre-override value after a certain time period of no communication.  A “bit 
mask” is associated with the object, and is used to determine the current 
state of the BO by modifying the point’s data at the bit location(s) indicated 
in the bit mask.  When the BO’s current state is set to “1” by the NCU, then 
the bit(s) of the point’s data indicated by a “1” in the bit mask are set.  
Similarly, when the BO’s current state is set to “0” by the NCU, then the 
bit(s) of the point’s data indicated by a “1” in the bit mask are cleared.  The 
point data’s least-significant bit (LSB) is bit #0, and the most-significant bit 
(MSB) is bit #15.