Instruction Manual

Glossary
Communications Specification 85
LSB Least Significant Byte. For all two-byte data types, the LSB is transmitted
before the MSB (Most Significant Byte) in the packet.
MLS Modular Loop System. A Watlow Anafaze controller.
MSB Most Significant Byte. For all two-byte data types, the MSB is transmit-
ted after the LSB (Less Significant Byte) in the packet.
NAK Not Acknowledged. A control code that signals that a syntactically incor-
rect message packet has been received.
Nibble A group of four bits or half a byte.
Packet A packet consists of a sequence of bytes in a specific format; it can be as
large as 256 bytes of data. Information is exchanged between host soft-
ware and the controller in packets.
Parity Error detection coding for serial communications. MLS, CLS and IRC2
controllers use no parity.
Precision
parameter
Indicates the decimal format for controller parameters such as process
variable, setpoint, etc.
Proportional
Band (PB)
The parameter that users alter from the front panel to set the proportional
control action, expressed in engineering units of the process variable.
Proportional
control action
Control action with a continuous, linear relationship between the output
value and the difference between the setpoint and the process variable.
Protocol A set of rules for the timing and format of messages in the network.
Pulse input An input for CLS controllers that measures a digital pulse signal.
Recipe See Job.
SDAC Serial Digital Analog Converter. A high-precision digital-to-analog con-
verter for control outputs.
Serial commu-
nications
Communications between a computer and another device (controller, for
example). Watlow Anafaze hardware supports two formats: RS-232 for
single device at short distances, and RS-485 for multiple devices at longer
distances.