Register Mapping; 1: Register Mapping Overview; Channel Status Holding Registers - Honeywell CGW-MB Installation And User Manual

Register Mapping

devices as long as the client continues to send analog value requests for points L1M1
through L1M10. When the client stops polling at 10 minutes, the CGW-MB will stop
polling the NFN after the Analog Value Time Out expires.
Use Case 3: A client requests analog values from the points L1M1 through L1M10. After
10 minutes of polling on a 10 second interval, the client requests analog values from the
points L1M20 to L1M22.
Result: The CGW-MB sends back zeros in response to the first request for analog values
from the points L1M1 through L1M10. The CGW-MB sends back actual values on the
second request from the client 10 seconds later. The CLSS Gateway mainboard
continues to poll these devices as long as the client continues to send analog value
requests for the points L1M1 through L1M10. When the client sends a request for analog
values from the points L1M20 through L1M22, CLSS Gateway mainboard waits till the
timeout happens and then the CGW-MB immediately sends back zeros in response to the
first analog value request from these points and starts polling L1M20 through L1M22.
The CGW-MB only polls the points specifically requested.
Use Case 4: A client requests analog values from the points L1M1 through L1M10. After
10 minutes of polling on a 10 second interval, the client requests analog values from the
points L1M5 through L1M12.
Result: The CGW-MB sends back zeros in response to the first request for analog values
from the points L1M1 through L1M10. The CGW-MB sends back actual values in
response to the second request from the client 10 seconds later. The CGW-MB continues
to poll these devices as long as the client continues to send analog value requests for the
points L1M1 through L1M10. When the client sends a request for analog values from the
points L1M5 through L1M12, the CLSS Gateway mainboard immediately sends back
zeros in response to the first analog value request from points L1M11 and L1M12 (since
these are newly requested points) and it sends back actual values in response to the
continuing analog value requests for points L1M5 through L1M10 (since it already has
been polling these points). The CLSS Gateway mainboard stops polling points L1M1
through L1M4 and starts polling points L1M5 through L1M12.
Use Case 5: A client requests analog values from the points L1M1 through L1M15.
Result: The CGW-MB sends back an exception response because it can only process
requests for up to 10 analog values at a time. The client should request and receive
values for L1M1 through L1M10 and then send a request for L1M11 through L1M15.
Note that the first request for analog values from a valid range of points is considered an
initialization request, which returns zeros.
7.21 Register Mapping
7.21.1 Register Mapping Overview
The CGW-MB uses 16-bit registers. One Modbus Input register and one Modbus Holding
Register are allocated for each device address. These registers represent a contiguous
address mapping of all devices and points.
NOTE: You can reserve 300 registers for device type registers.

Channel Status Holding Registers

Each channel status holding register is placed either into the Upper Byte or the Lower
Byte.
• Upper Byte: Has general status information about the point.
CGW-MB Installation and Users' Manual | P/N:LS10248-000HW-E | REV.G | JUL/31/2022
Modbus Communications
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