Pentair 920 Series Installation, Operating And Maintenance Instructions page 41

the 920 control module, these parameters need not be configured. All these parameters are
common for both of the two control points—Point A and Point B, except the HTCBUS™ ADDRESS,
MODBUS™ ADDRESS, and MODBUS™ SUB ADDRESS settings, as applicable.
3.9.1 protoCoL
purpose: Defines the communications language used by the controller to communicate with other
devices.
setting: HTCBUS or MODBUS ASCII (V3.11+) or MODBUS RTU (V3.11+)
procedure: Select the HTCBUS™ protocol when communicating with existing Pentair
Thermal Managament Heat Trace Control products, including the Model 780/GCC-9000 Group
Communications Controller.
If you are communicating directly with the controller using a different device, select the MODBUS
protocol. For a detailed description of the controller's MODBUS mapping, please refer to the
separate Raychem 920 Series Heat Trace Controller—Modbus Protocol Interface Mapping
document (Pentair Thermal Managament reference H57366 ).
3.9.2 htCbus™ address
purpose: Defines the communications address to be used by the controller when using
the HTCBUS™ protocol to communicate with a Model 780/GCC-9000. When in the Point A
configuration menu, this sets the Point A HTCBUS™ ADDRESS; when in the Point B configuration
menu, this sets the Point B HTCBUS™ ADDRESS. Either may be set independently of the other.
range: 1 to 16,777,215
procedure: Set the communications address as desired. This must be an address unique to the
entire communications network to avoid messaging conflicts. The HTCBUS™ protocol must be
selected in order to set the HTCBUS™ ADDRESS.
Important: A unique HTCBUS™ communications address is always assigned by Pentair Thermal
Managament and identified by the label on the front of the 920 control module (see Figure 3.1).
Use the preassigned address whenever possible to minimize the chances of an address being
duplicated in the user's system.
3.9.3 modbus address (v3.11 and up)
purpose: The MODBUS™ ADDRESS, along with the MODBUS™ SUB ADDRESS, defines the
communications address to be used by the controller when using either MODBUS™ protocol to
communicate with a MODBUS™ compatible device. When in the Point A configuration menu, this
sets the Point A MODBUS™ ADDRESS; when in the Point B configuration menu, this sets the Point
B MODBUS™ ADDRESS. Either may be set independently of the other.
range: 1 to 247
procedure: Set the communications address as desired. Together with the MODBUS™ SUB
ADDRESS, this combination must be unique to the entire communications network to avoid
messaging conflicts. Either MODBUS™ protocol must be selected in order to set the MODBUS™
AD-DRESS.
3.9.4 modbus sub address (v3.11 and up)
purpose: The MODBUS™ SUB ADDRESS, along with the MODBUS™ ADDRESS, defines the
communications address to be used by the controller when using either MODBUS™ protocol to
communicate with a MODBUS™ compatible device. When in the Point A configuration menu, this
sets the Point A MODBUS™ SUB ADDRESS; when in the Point B configuration menu, this sets the
Point B MODBUS™ SUB ADDRESS. Either may be set independently of the other.
range: 0 to 31
procedure: Set the communications sub address as desired. Together with the MODBUS™
ADDRESS, this combination must be unique to the entire communications network to avoid
messaging conflicts. Either MODBUS™ protocol must be selected in order to set the MODBUS™
SUB ADDRESS.
Important: Since a 920 HTC does not use all 65,535 data addresses available for each
MODBUS™ ADDRESS, this data address range is subdi-vided to allow up to 32 HTCs to share the
INDUSTRIAL HEAT TRACING SOLUTIONS EN- Raychem920series-IM-H56874 05/15 41 / 82