Honeywell VRX180 user manual Serial Communications Prompts

Programming Function Blocks and Features

4.21 Serial Communications

Serial Communications is an optional feature that lets the instrument exchange data with a host device (a PC running Honeywell or other compatible software) on an RS422/485 data link. Using Modbus RTU protocol, this link can be used to transfer configurations and data. Set up the link as follows.

Table 4-67 describes the Serial Communications prompts.

Table 4-67 Serial Communications Prompts

Prompt		Range/Selections		Definition
UNIT ADDRESS	1-254		Enter the unit’s address. Use a number once only so that each
			address on the link is unique.
BAUD RATE	1200, 2400, 4800,		Enter the speed of data transfer. All equipment on the link must
	9600, 19200, 38400,		be set to match the host setting.
	76800.
DOWNLOAD		YES, NO	Set to YES to prevent configurations from being downloaded from
LOCKOUT			a PC with SCF software.
BYTE ORDER		FP_B : Big Endian	This feature allows a user to select the byte order for a floating
		FP_BB : Big Endian	point register.
		with Byte swap
		FP_L : Little Endian	Example for 25.38 :
		FP_LB : Little Endian
		with Byte swap
				Byte order	Result
			FP_B	0123	41CB0A3D
			FP_BB	1032	CB413D0A
			FP_L	3210	3D0ACB41
			FP_LB	2301	0A3D41CB

Video Recorder – User Manual 161