ACR Binary Parameter Access Examples

Supplement to ACR Programmers Guide,Binary Host Interface

Products: ACR9000,9030,9040,9600,9630,9640, AR-xxCE (Aries Controlller)

Binary parameter access provides a method of reading from and writing to single system parameters on the controller. Unlike binary data packets, binary parameter access uses the actual parameter number. There are no groups or masks.
A parameter access header consists of a Header ID ( 0x00 ) followed by a Packet ID code and a 2-byte parameter. The Packet ID codes for the different types of packets are shown below. The following pages define each of the packets in detail.

Packet ID Codes
Code	Packet Type	Description
0x88	Binary Get Long	Receive long integer from controller
0x89	Binary Set Long	Send long integer to controller
0x8A	Binary Get Float	Receive Float value from controller
0x8B	Binary Set Float	Send Float value to controller

When using the Binary Parameter Access, the parameter is converted to hex. The parameter is a 2-byte value sent low-order byte first. Here are some examples:

P12288(current position, axis0) converts to 30 00. Request is sent to controller as 00 88 00 30
P12546(actual position, axis1) converts to 31 02. Request is sent to controller as 00 88 02 31
P8193(vector velocity) converts to 2001. Request is sent to controller as 00 8A 01 20

http://VB.Net example for formatting the byte packets

Imports System.BitConverter

PublicFunction GetLongPacket(ByVal iParm AsInteger) As System.Array

Dim bArr(3) As Byte

Dim byteParm(1) As Byte

bArr(0) = &H0

bArr(1) = &H88

byteParm = BitConverter.GetBytes(iParm)

System.Array.Copy(byteParm, 0, bArr, 2, 2)

Return bArr

End Function

23-Mar-2012