Submittal Sheet

7800 SERIES S7800A2142 KEYBOARD DISPLAY MODULE
32-00110—05 58
NOTE: “Device Data Ready” and “S7800 Compatibility” bits can be used to quickly check device availability and compat-
ibility then read/write registers of only these devices.
Response Message Format for Function Code 17
This format is device specific and is only available for the 7800 SERIES burner control. See Table 13.
Table 17. Response Message Format for function code 17 (11h), (26 bytes).
a
Slave ID: Always 0x78 when using RM78xx or EC78xx Relay Modules(1 byte) (byte 3).
b
Run Indicator Status: Always FF=ON (one byte) (byte 4).
c
Device Description: 16 character ASCII OS number for the Burner Control (11 bytes) (bytes 1-11).
01B7-
01B8
40440-
40441
Unused U32
01BA 40443 Device Data Ready U16 Device data was properly received by S7800.
Bit(s)
Device
0 RM78XX
3 EC78XX
4-15 Unused
01BB 40444 S7800 Device Compatibility
with Current Software
Revision
S7800 Software Revision
Compatibility with Legacy
Software Revisions.
U16 Device is compatible with the S7810M version
Bit Device
0 RM78XX
3 EC78XX
4-7 Unused
Used for indication of S7800 revision compatibility.
Bit(s)
Compatible with:
8 Series 2
9-15 Future
01BC 40445 Modbus U32 Endian R/W U16 Endian order for U32 registers:
0 = Big-Endian (MS U16 first)
1 = Little-Endian (LS U16 first)
Slave
Address
Function
Code
Byte
Count Slave ID
a
Run Indicator
Status
b
Device
Description
c
N/A CRC CRC
Byte 0 1 2 3 4 5-15 16-23 24 25
Table 16. ModBus™ Register Assignments. (Continued)
Address
(hex)
Register
(dec) Parameter Name
Read/
Write Format Notes