Page 77 - GuardII+ Series 4208 Platform EV User Manual

Appendix

8.4. Modbus Slave Timing

NOTE:
As described in Section 4.2, GuardII+ updates the EV Modbus data
registers after every measurement cycle, which occurs every 6-10
seconds; however, polling the monitor too quickly is just wasting network
bandwidth.

Each monitoring technology in the GuardII+ Series 4208 Platform has its
own measurement cycle; so If the monitor has other monitoring
technologies installed, those other technologies may provide Modbus
updates more rapidly.
To achieve the best performance when polling GuardII+’s EV Modbus data registers, the
following configurations of the polling system should be used:
• Modbus response timeout should be set to no less than 5000ms

• Modbus polling should occur no more often than once every 5 seconds.

8.5. Using PLC-Style Addressing

GuardII+ uses protocol-style Modbus addressing (Base 0), not PLC-style Modbus
addressing (Base 1). When using PLC-style addressing to acquire Modbus data from
GuardII+, this will cause an address shift.
NOTE:
When accessing GuardII+ data registers using PLC-style addressing, the
address must be increased by 1.

Sample Addresses using Modbus (Base 0) Addressing
Address Data Notes
30100 Synchronization The synchronization status for the measurement:
Status 0 = No data is available
1 = Synchronized
2 = Stable; not at rated speed, but low
variation
3 = Unstable; not at rated speed with high
variation
4 = No rotation detected
30101 Shaft RPM This is the RPM detected from the Shaft Trigger.
This is a float value.
If the Shaft Trigger is not available, this is reported
as ‘0’
30103 EV1 Measurement EV Input 1 measurement status:
Status 0 = No data is available
1 = Measurement data is valid
2 = Input signal is too large
3 = Hardware error detected.

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