Pressure Systems 98RK, 9816 user manual Bit# Chan# Binary Hex

Pressure Systems, Inc. 98RK-1 & 9816 User’s Manual©

In the following example 20-bit (5-hex digit) position field, internal channels 16 and 1, and both external P & S pressures, are selected:

Bit#

Chan# Binary

Hex

19	18	17		16	15	14	13		12	11	10	9		8	7	6	5		4	3	2	1		0
			P	S	16	15	14		13	12	11	10		9	8	7	6		5	4	3	2		1
0	0		1	1	1	0		0	0	0	0		0	0	0	0		0	0	0	0		0	1
		3					8					0					0					1

When all applicable internal channel bits are set in the position field (i.e., FFFF for a 16-channel 9816 module), it specifies all internal channels. Alternately, some commands allow a missing position field to designate all internal channels, but only when there are no other parameters following the position field in the command. Optionally, the hex position field may be reduced from 5 to 4 digits when no external (P & S) channel bits need be set (=1) in the discarded high- order hex digit). In two commands ('C' and 'c'), only the position field may have 1-5 digits, as needed, to specify progressively higher numbered channels.

A position field bit map may specify the number and order of datum Note data from module). In either case, the order of the datum fields is

from highest requested channel number to lowest requested channel number.

3.1.3.4Datum Fields

Any datum fields in a command generally contain data to be sent to the module, usually specified by a position field bit map. In some commands (when data are to be received from a module instead) no datum fields are required in the command itself, but the position field bit map is still used to specify the order that data are returned in the command’s response. In either case, the order bits are set (to 1) in the position field bit map (highest channel # to lowest channel #, left to right) is the order these datum fields are received or sent. The special external P & S channels are considered higher #’s than any internal channels #’s (16-1).

Each datum field may be variable in length, whether part of the command itself or the command’s response. In its most common format, a datum begins with a space character (‘ ’), and is followed by an optional sign, decimal digits, and decimal point, as needed (e.g., - vv.vvvvvv). For other formats it may be a hex digit string or pure binary number.

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