ProSoft Technology MVI69-HART - Manual (Page 94)

Reference MVI69-HART ♦ CompactLogix Platform
User Manual HART Multi-drop Master Communication Module
Page 94 of 169 ProSoft Technology, Inc.
March 29, 2012
Warm Boot (Block 9998)
This block is sent from the CompactLogix or MicroLogix processor to the module
(output image) when the module is required to perform a warm-boot (software
reset) operation. The following table describes the format of the control block.
Offset Description Length
0 9998 1
1 to n Spare n
n=60, 120, or 240 depending on the Block Transfer Size parameter (refer to the configuration file).
Cold Boot (Block 9999)
This block is sent from the CompactLogix processor to the module (output
image) when the module is required to perform the cold boot (hardware reset)
operation. This block is sent to the module when a hardware problem is detected
by the ladder logic that requires a hardware reset. The following table describes
the format of the control block.
Offset Description Length
0 9999 1
1 to n Spare n
n=60, 120, or 240 depending on the Block Transfer Size parameter (refer to the configuration file).
5.2.5 HART Channels
The MVI69-HART module supports the HART protocol as a Master on up to two
channels. Each channel is individually configurable.
The HART protocol uses the Bell 202 standard frequency shift-keying (FSK)
signal to communicate at 1200 baud, superimposed at a low level on the 4 to 20
mA analog measurement signal. Having an average value of zero, and FSK
signal causes no interference with the analog value. The HART devices are
powered from this 4 to 20 mA analog loop.
Both HART protocol channels in the module generate the Bell 202 FSK signal to
communicate in multi-drop mode with up to 15 HART devices and provide up to
250 mA supply for analog loop.