•  SupervisoryLink:  Use this channel if the H201Ti must be set to Hydran protocol 
and has to communicate with an H201Ci Controller. 
•  LocalUSB  MODBUS:  Use  this  channel  if  the  H201Ti  must  be  set  to  ModBus 
protocol  and  has  to  be  connected  directly  to  a  host  computer  running  the 
Perception software.  For this connection, use the H201Ti’s USB female connector 
located on the side of the CPU module.  The USB link is used only occasionally or 
for brief periods of time during the initial verification or maintenance procedures. 
•  SupervLnk  MODBUS:  Use  this  channel  if  the  H201Ti  must  be  set  to  ModBus 
protocol  and  has  to  be  connected  via  an  USB  to  RS-485  converter  to  a  host 
computer  running  the  Perception  software  or  to  communicate  with  an  H201Ci 
Controller. 
Note: The H201Ti’s microprocessor only gives access to one channel at a time. 
5.5.6.2  Comm Mode 
This function is used to select the communication mode between the Hydran 201Ti and 
the Hydran Host software. There are two possibilities: 
•  Call  OnAlarm:    In  this  mode,  the  H201Ti  communicates  with  the  Hydran  Host 
through  a  telephone  line  when  a  gas  or  fail  alarm  condition  is  detected.    The 
operation of this mode can be tested using the Communication; Force HostCall 
command (see Section 5.5.6.5).  The frequency and number of call attempts meet 
the normal regulations of telephone companies. 
•  AnswerOnly:  In this mode, the H201Ti remains inactive until being questioned by 
the host computer running the Hydran Host or any other SCADA system. 
5.5.6.3  MODBUS Parity 
This function is used to select the ModBus Parity communication setting and it can be 
set at None, Odd or Even. 
This  setting  is  relevant  and  shall  be  properly  configured  only  when  the  Comm 
Channel and Default Channel are set to LocalUSB ModBus or SupervLnk MODBUS. Else, 
when 201Ti is set to Hydran protocol (Comm Channel and Default Channel are Local USB 
or Supervisory Link), this setting is ignored. 
5.5.6.4  Baud Rate 
This function is used to set the serial communication rate of the Hydran 201Ti.  The 
communication  can  be  set  at  1,200,  2,400,  4,800  or  9,600  bps  (bits  per  second).    All 
H201Ti’s belonging to one network must be set to the same baud rate. 
If the BaudRate parameter is changed and if the H201Ci Controller is equipped with a 
modem,  always  execute  the  Communication;  Force  HostCall  command  (see  Section 
5.5.6.5 below) immediately after the modification. 
Note:  The communication rate of the H201Ti’s must be the same as the one set in the 
Hydran Host software (see the Hydran Host Software Manual).