Precision Digital PD6080 - Manual (Page 9)

PD6080/PD6081 Super Snooper Modbus Scanner Instruction Manual
9
SPECIFICATIONS
Except where noted all specifications apply to operation at +25°C.
Operating Modes
MASTER Processes data read from Modbus RTU slave devices. It polls up to 16 process
variables from 1 to 16 slave devices. The Master is capable of scanning the
selected PVs, scaling the data, triggering relays, performing math operations,
and driving the analog outputs.
SNOOPER Listens to the Modbus traffic and picks up a specific register or registers being
polled by a master device from a specific slave device and processes the data
being read. The Snooper mode handles the data the same way as the Master.
SLAVE Processes data sent to it from a Modbus RTU master device.
Note: The relays and the 4-20 mA outputs are functional in all modes.
Master & Snooper Settings
PV NUMBER PV1–PV16 Enable or disable the process variables to be polled by the Master.
SLAVE ID Assign the slave ID or address (1-247, 256-259 for mA or volts inputs)
containing the process variables to be displayed by the selected PV.
FUNCTION CODE Select which Modbus function code (03, 04, or 65) to use in reading the slave device.
REGISTER
NUMBER 5 digit: 30001-39999, 40001-49999, or 1-65,536
6 digit: 300001-365536 or 400001-465536 (Function Code 65 N/A here)
Specifies which register(s) to read in the slave device. Range is dependent on
Function Code selection (65, 04, or 03) and digits selection (5 or 6).
DATA TYPE Select the data format that the slave device uses. Select between Short integer
(2 byte), Long integer (4 byte), or floating point (4 byte), Signed or Unsigned
(integer only) and byte order: 1234, 4321, 2143, or 3412 (big-endian vs.
little-endian, or swapped).
POLL TIME 1.0 to 99.9 sec. Time between read-commands (Master mode).
SLAVE
RESPONSE
TIMEOUT 0.0 to 99.9 seconds: Time allowed for the slave to respond before the scanner
generates a communication break condition. The master polls the slave 3
times before starting the response timeout timer.
Slave/Snooper mode: Time the scanner will wait for new data before going into
break condition.
Slave mode: Programming 0 disables the timeout; the last value received will
be displayed indefinitely.
COMMUNICATION
BREAK Displays “brEAK” after the Master has polled the slave device 3 times and the
response timeout has elapsed. The Snooper and Slave modes go into break
condition after no new data is received within the response timeout window.
Relays can be programmed to go on, off, or ignore the break condition. The
analog outputs can be setup to generate a fixed mA current when a break
condition is detected.