Sel SEL-2600, Instruction Manual, Page: 11 / 16

Date Code 20000525 SEL-2600 RTD Module
Data Packet Definition
11
Data Packet Definition
The SEL-2600 RTD Module sends a binary data packet every 0.5 seconds. The
packet contains data for all four types of supported RTDs so no settings are required
in the SEL-2600 (patent pending). Using the SEL-2800 Fiber-Optic Transceiver,
any EIA-232 device can be configured to understand the binary data packet con-
tents shown in Table 3.
Table 3 SEL-2600 RTD Module Data Packet Definition
Table 3 SEL-2600 RTD Module Data Packet Definition
Data
Value
Data
Size
Description
A546h 2 bytes Beginning of Message Code
74h 1 byte Message Length (116 bytes)
0000000000h 5 bytes Routing Value (0)
00h 1 byte Status Byte
12h 1 byte Function Code
00h 1 byte Sequence Byte
00h 1 byte Pad Byte
xxxxxxx 4 bytes Milliseconds Since SEL-2600 Power-Up
or Clock Rollover (86,400,000 ms/5265C00h)
xx 2 bytes Device Status (Bitmap)
Bit 0: Power Supply Status
Bit 1: RTD Circuitry Status
(0 = okay; 1 = fail)
Bit 2: Watchdog Timer Status
(0 = okay; 1 = fail)
Bit 3: 8 V Power Supply Status
(0 = okay; 1 = fail)
Bit 4: 5 V Power Supply Status
(0 = okay; 1 = fail)
Bit 5: –5 V Power Supply Status
(0 = okay; 1 = fail)
Bits 6–14: Unused, Zero
Bit 15: Contact Input State
(0 = deasserted; 1 = asserted)
xxxx 96 bytes
a
Temperature Data (
•C)
Word One: PT100 temperature
Word Two: NI100 temperature
Word Three: NI120 temperature
Word Four: CU10 temperature
(Continued)