RTK Series 725 Annunciator
78
P725 to P725 Connections
For applications where local and remote annunciators are required two or more P725 annunciators
can be interconnected. In the normal situation one of the annunciators will monitor the standard volt-
free alarm contacts or voltage inputs and indicate the alarms as normal. This alarm information is
then transmitted on the serial communications to another P725 annunciator using either two or four
wires for the communications. These systems are interconnected as shown later in this section.
System 9000TS To P725 Annunciator
The System9000TS Annunciator from RTK Instruments can also be used as described above to
monitor a number of alarm contacts and transmit the information via the serial communications to a
remote P725 annunciator. The System9000TS can optionally have a display to indicate alarm
information or simply operate as a data gathering and transmission device. Please refer to our sales
office for further information on these systems.
Modbus Communications
Full details on how to use modbus ASCII and modbus RTU protocols are not given within this manual
as they are well covered by more specialised manuals. A brief overview of the main features is
shown below.
Modbus Function Codes
The function code field tells the addressed 'slaves' what function to perform. The only relevant
function codes when communicating to the P725 annunciator are as follows:-
03 Read register This reads 16 bit data registers containing alarm information
06 Write register Writes data to 16 bit register. This data request can be used
as an alternative alarm input source.
Error Check
The error check is either LRC (Longitudinal redundancy check) or CRC (Cyclic redundancy check)
depending on whether ASCII or RTU modbus is selected.
Software
RTK Instruments can supply comprehensive monitoring software for use with the 725 Series alarm
annunciator. This can be configured as an alarm/event management system with user generated
custom displays to monitor plant wide system operation.
To Next Page
Loading...
Need help?
General
