Table 3 - Serial Port Dip Switch Settings; Figure 26 - Serial Ports Dip Switch Default Settings - Honeywell HC900 User And Installation Manual

Setting serial ports S1 and S2 to RS-232 or galvanically isolated RS-485
For legacy systems, S1serial port default setting is RS-232; S2 serial port default setting is RS-485. Each
port can be set to RS-232 or RS-485 (not shown).
For new systems, the serial ports S1 and S2 are galvanically isolated RS-485 unterminated (See Table 3
below).
Functionality is determined by DIP switch setting on, see the following figure. To change either port's
setting, use the switch settings in Table 3. Use a small slotted screwdriver or paperclip to gently move the
DIP switches. If you push too hard you could damage the switches or nearby circuitry. Avoid using pencils
because the point could break and cause damage.
Revision 6
21 April 2017
Table 3 – Serial port DIP switch settings
Figure 23 – Serial Ports DIP Switch default settings
HC900 Process & Safety Controller User and Installation Manual 43