COMMISSIONING 
 
 
152  Service Manual    Part No.: 4417340 Revision 1 
  954 SmartServo FlexLine
 
  Multi-drop  mode  supported  to   connect   more   than   one  
HART- compatible device on HART bus. For operating the 
device in Multi- Drop mode, user needs to select the polling 
address to a non-zero value.  Making  the  polling  address  to  a 
non-zero  value  makes  the output current mode to 
Fixed_4_20_MA (4 mA fixed). Non-zero polling address will 
automatically make the output current mode to Fixed_4_20_MA.  
All  the  HART-compatible  devices  connected  over  the  HART 
bus must have different polling addresses. Multi-drop mode is 
supported only in Passive mode of loop configuration. When 
the output current mode  is  set  to  Standard_4_20_MA, the  polling 
address  of  the  device must be made zero. 
  When the device is not in multi-drop mode (STANDARD_4_20_MA 
mode selected) then the output current follows the changes in 
linked PV value. 
  Scanning of each linked available PV, SV, TV and QV on the 
CAN- bus with frequency of 1 Hz. That means all the available 
linked variables are scanned every 1 second. 
  The analog output is refreshed every 1 second, even  if  there 
is  no  change in  the  scanned variables. So,  the  watchdog for 
analog output is automatically implemented. If the output is not 
refreshed within 45 seconds then a watchdog to analog output 
is generated and the output is forced to 0 mA. 
  During startup, the analog output of the HCI-HAO module is kept 
low (< 0.5 mA). This  value  will  be  there  till  initialization takes 
place. Once  the  normal operation starts  the  output  will  follow 
the linked PV depending upon the output mode setting. 
  Manual overwrite mechanism.  This  is  a  standard  FlexConn 
func-tionality.  Separate configuration and  command entities 
are  defined for this. See 7.3.9.5 - Board Commissioning. 
 
7.3.9.4  Calibration of the HCI-HAO 
A calibration provision is given, which is used to accurately map the 
analog output between 4 -20 mA using the two range values entered for 
Primary Variable. 
Following table lists all entities required for calibration. 
Entity  Data Type  Type 
[Analog Output at 4 mA] 
Float  non-volatile R/W 
[Analog Output at 18 mA] 
Float  non-volatile R/W 
[Calibrate at 4 mA] 
Undefined  command 
[Calibrate at 18 mA] 
Undefined  command 
[Enter Calibration Mode] 
Undefined  command 
[Exit Calibration Mode] 
Undefined  command