Teledyne powerpod 400 Serial Communication, Commands, Set Point Queries, Alarm/Flag Queries

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10.9. SERIAL COMMUNICATION

Follow the instructions in the section, WIRING THE POWERPOD-400for cabling and proper pin out for serial communication with the unit. After insuring that the POWERPOD-400is wired properly, the unit must be set up following the instructions in the section entitled, External Communications Setup.

The instruction set for the POWERPOD-400can be divided into two different types. They differ only in that they

1.Write a command only or

2.Write a command and read a response.

Taking liberty with this vernacular, they may be differentiated using the terms COMMAND or QUERY. The entire set of instructions can be found in Appendix B.

10.9.1. Commands

Typical RS-232 command structure is as follows: CMNDn<value>Cr

For example: To change channel three’s high alarm value to 75.00, send A3H075.00Cr.

RS-485 commands require only that an asterisk and the unit’s address precede the RS-232 Command. Using the same example as above with a unit whose address is 10 (default), send *10A3H075.00Cr.

When the POWERPOD-400is the terminating unit on a 485 bus, two jumpers, CJ1 and CJ2 can be shorted to add the required terminating resistors. Remove two machine screws from the rear of the top cover. Slide the cover off. The two jumpers are near the serial communication connectors.

10.9.2. Set Point Queries

Queries are used when information from the unit is required. Each query is followed by a response from the POWERPOD-400.

In this case, the query is asking for a programmed value. Specifically, the set point of channel three, which happens to be set at 50.00 of 100.00.

Sent

SP3Cr

Response

SP3 050.00

10.9.3. Alarm/Flag Queries

The state of the high and low flow alarms for each channel can be monitored via the DB-15 connecter (J8) on the rear panel for immediate action from an alarm situation but the Totalizer set points can only be monitored by reading a memory location’s Boolean setting via serial communication.

As shown in the section, Setting Limit Alarms, to simply QUERY channel three’s high alarm set point, send A3HCr. Expect a response similar to A3H 075.00. The actual state of the alarm can be polled using the STATUS query.

STCr

Which results in a response similar to

STATUS

OCA : CH1 AUTO CH2 CLOSED CH3 OPEN CH4 AUTO

HI/LO: 0/0 0/1 1/0 0/0

OCA is short for OPEN/CLOSED/AUTO.

HI/LO stands for the high flow limit alarm or the low flow limit alarm. One must parse the states if digital tests are to be conducted.

164-122012 PowerPOD 400

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Contents Teledyne Hastings Manual Print History Table of Contents Four to Twenty Milliamp Operation Power Quick Start InstructionsSafety Features Front Panel LockoutPower Selection Specifications PowerPod-400 Specifications TableFront Panel Channel Number Select KeysRear Panel Power WiringCommunications Alarms Transducer ConnectionsAnalog Signal Followers Power ON/OFF Changing the Command SET PointManual Operation Override OpenSetting a Channel to Directly Meter Incoming Signals Setting a Channel to Auto ControlSetting a Channel to Display the Totalizer Function Mode Reset Value Choosing RS-232 Communication External/Remote OperationChoosing RS-485 Communication Setup/Cal Mode Entering the SETUP/CAL ModeDisplay Setup Blanking a Display Line/ChannelSelecting Unit-of-Measure Setting A/D Conversion Rate FilterSelecting Gas ID Front Panel Lock Out Totalizer SetupCount Up to a Set Point External Communication Setup RS-232 SettingsRS-485 Settings Count Down from a Set PointSelecting the Analog Signal Level Zero to Five Volt OperationZero to Ten Volt Operation Four to Twenty Milliamp OperationSetting Limit Alarms Setting a Single Channel’s High LimitSetting a Single Channel’s Low Limit Setting a Single Channel’s HysteresisSetting Ratio Control Parameters Enabling Ratio ControlResetting the Zero Only Calibrating a Channel to ITS Incoming SignalsResetting the Span Only Resetting Zero and Span Setting a Multiplication FactorCommands Alarm/Flag QueriesSerial Communication Set Point QueriesPowerPOD PowerPod-400 Serial Commands Appendix aPowerPod-400 Serial Commands Contd Appendix a Notes ApppendixCB Name Rate TotalGas ID Table Page 1 Gas ID Table Page 2 Setting the Zero & Span PowerPod-400 Power Supply/Totalizer Appendix DZeroing Unit 4 to 20 mA Range Spanning Unit Transducer POWERPOD-400 PowerPOD Drawings Warranty Warranty Repair Policy
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