B&B Electronics manual 232DRIO Commands, Equivalent Values, Syntax, Function Command Response

Table 3.1 – 232DRIO Commands

Function	Command	Response
Set Output Lines	!0S{…}	No response
Read I/O Lines	!0R	{…}
Set Output Lines	#0S{…}{~…}	No response
Read I/O Lines	#0R	{…}{~…}
Symbol: {…}	represents one byte

<…> represents a numeric value

~complement of the specified data byte

Before going into the specifics of each command, it is important to understand that a byte has a numeric value from 0 to 255. The byte's value can be represented in decimal (0 -255) format, hexadecimal (00 - FF) format, binary (00000000 - 11111111) format or as an ASCII character. The fixed bytes of each command will be represented as ASCII characters, for example: “!0R”. Refer to Table 3.1. However, it is important to remember that an ASCII character has a numeric value. Example: the ASCII “0” (zero) does not have a value of zero but has a value of 48. The decimal and hexadecimal equivalents of some ASCII characters are shown in Table 3.2. Some commands require an additional data byte to complete the command. These data bytes may be represented in any of the formats listed above. Refer to Appendix A for more ASCII and decimal equivalents.

Table 3.2 – Equivalent Values

ASCII	Decimal	Hexadecimal
!	33	21h
#	35	23h
0	48	30h
R	82	52h
S	83	53h

Syntax

Command strings consists of three to five bytes depending on commands used for normal or harsh environments. The first byte is always the start of message byte. The start of message byte is either the ASCII “!” character (normal) or the ASCII “#” character (harsh). The second byte is the address byte. This byte allows each unit to have a unique address (useful in RS-485 networks). Since the 232DRIO uses RS-232 communications, this byte is always the ASCII “0” character and can not be changed. The next byte is the command character. This byte is ASCII character and

10	232DRIO-0308 Manual
B&B Electronics --	PO Box 1040 -- Ottawa, IL 61350

PH (815) 433-5100 -- FAX (815) 433-5104