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CAMAC DIGITAL OUTPUT
32 CHANNEL ISOLATED DIGITAL OUTPUT MODULE (IDOM)The Model 5568 is a single-width, 32 channel, opto-isolated, general purpose digital output module controller. The unit was designed for continuous operation, but also has a channel-selectable pulse output mode, with independently variable pulsewidths. Individual outputs may be group-overwritten, selectively set or cleared, selectively pulsed (on or off), and may further control other pulsed outputs at the start or end of a pulsed output. The output width in the pulsed mode may be a predefined value, or may be set to a range of values using CAMAC commands. Various outputs may be responding to any of the above commands concurrently. In addition, channels to be pulsed may be preset with pulse width, channel-to-trigger number, and start/end trigger options, with the actual execution deferred. Action may be later initiated on several different channels using a selective pulse command to cause execution of the preset sequences. Up to 16 commands may be stacked into the FIFO at rates up to full CAMAC DMA speeds, for serial processing by the microprocessor. Maximum response time, from Dataway command to channel output: 10 milliseconds per command, times the number of FIFO stacked commands. Read commands are available to monitor the 32 outputs and status data.
IDOM outputs are individually opto-isolated, with each output floating. The outputs are specified to switch 75VDC circuits. By changing the opto-isolators the switching voltage may be increased to 100VDC. If the IDOM is to be used for 120VAC control, it is recommended that a 16 channel output group be dedicated for this application and not mixed with low-voltage DC circuits.
Each 16-channel output group may be overwritten, selectively set or reset, pulsed on or off, reset or read back.
Two commands both related to pulsed output and each relating to one channel at a time operation are setting variable output pulse widths and loading sequenced information for Pulse Transfer Mode operation.
The output pulse width is dependent upon the basic time unit (TU, equal to n counts of the crystal-controlled microprocessor clock), a default output width (mTU) which is defined by the program in EPROM, and a CAMAC command which may be used to load count (in the range of 1 to 255) for a specified output channel. If no count has been loaded prior to the pulsed output trigger, the width becomes the default value mTU.
Additional data contained in this command allows setting the pulse polarity (i.e. ‘on’ or ‘off’) and also either generating the pulse immediately, or deferring the pulse until a later trigger.
The unit may also be used to perform a delayed switch transition, in the following manner: Assume that an ‘on’ output is commanded to pulse on. At the time of the command, there is no change, as the output was already on. Then, at the end of the pulse period, the output would switch off, thereby effecting a delayed output. An ‘off’ channel, pulsed off, would effect a delayed turn-on.
Pulse Transfer Mode operation allows any preselected pulse to trigger any one other pulse, and the trigger may be selected to occur on either the leading or trailing edge of the pulse, regardless of pulse polarity. This command loads a channel with the number of another channel to be triggered, and a bit indicating the edge on which to generate the trigger. All execution is deferred, and must be initiated by either a subsequent command, or the trigger from another channel.
Command decoding is done by Field Programmable Logic Arrays (FPLAs). The FPLAs either select immediate execution of a command (Reads, Resets, and Test Status), or load the command and related data into a First-In-First-Out Memory (FIFO). X and Q responses are generated for each command as received, and each command is either executed or loaded into FIFO within a normal CAMAC Dataway cycle.
The FIFO is 16 words deep. This allows a sequence of 16 commands to be streamed to the module at maximum dataway rates, for execution by the slower microprocessor. Attempting to overwrite the FIFO will cause a Q response of 0.
The microprocessor is interrupt-driven by a signal generated by the FIFO when a command is ready at the FIFO output. The microprocessor accepts and completes operation on any given command prior to clearing the FIFO output and re-enabling the microprocessor interrupt.
The TU pulse counter is also interrupt-driven to insure reasonably stable pulse widths, regardless of other microprocessor activity. This interrupt is always enabled, and has been assigned the highest processing priority. Each time the interrupt occurs, the RAM counter for each active output pulse is decremented, and tested for zero. Transition of a counter to zero causes termination of the related output pulse.
As appropriate, the latch for each output is set on or off by the microprocessor. A CAMAC read of the outputs reads the latches.
| COMMAND | Q | ACTION |
|---|---|---|
| F0 A0 RD1 | 1 | Read channel 0-15 output latch, Q=1 if J1 and J2 pins C9 are both above +12 volts. |
| F0 A1 RD1 | 1 | Read channel 16-31 output latch, Q=1 if J1 and J2 pins C9 are both above +12 volts. |
| F1 A0 RD2 | 1 | Read channel data only, X=1, Q=1. |
| *Note: | For all write functions described below; X=1; Q=1 if the voltage on pin C9 of both output connectors is above +12 volts |
|---|
| F16 A0 WT1 | Write the W1-16 bits to channels 0-15 |
| F16 A1 WT1 | Write the W1-16 bits to channels 16-31 |
| F17 A0 WT2 | Write an output time interval to a specified channel |
| # W1-W5 = channel #, 0 - 31, encoded | |
| # W7 = polarity, 0 = pulse off, then on; 1 = pulse on, then off | |
| # W8 = execute, 1 = defer execution, 0 = execute immediately | |
| # W9-W13 = time units, 1-255 decimal | |
| F17 A1 WT2 | Define a transfer channel (channel to be triggered) |
| # W1-W5 = channel # to initiate transfer, 0 - 31, encoded | |
| # W8 = transfer polarity, 1 = transfer at the pulse start time, 0 = transfer at the end of the pulse time | |
| # W9-W13 = channel # to be triggered, 0 - 31, encoded |
| **Note: | Action to be taken as defined by a previous F17 A0 command to that channel. If undefined, the default is to pulse on for the default time interval. If the output is on, it will pulse off for the defined time interval. If the output was off prior to the command, it will go on after the defined time interval. The pulse period may be set by a prior F17 A0 command. If it has not been preset, the default pulse period is used. |
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| F18 A0 SS1 | Selective set channels 0 - 15 as defined by W1 - W16 |
| F18 A1 | Selective set channels 16 - 31 as defined by W1 - W16 |
| F19 A0 SS2 | Pulse on selected channed 0 - 15 output(s) as defined by W1 - W16 |
| ***Note: | If the output is off, it will pulse on for the defined time interval. If the output was on prior to the command, it will go off after the defined time interval. The pulse period may be set by a prior F17 A0 command. If it has not been preset, the default pulse period is used. |
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| F19 A1 | Pulse on selected channel 16 - 31 output(s), as defined by W1 - W16 |
| F21 A0 SC1 | Selective clear channels 0 - 15 as defined by W1 - W16 |
| F21 A1 | Selective clear channels 16 - 31 as defined by W1 - W16 |
| F23 A0 SC2 | Pulse off selected channel 0 - 15 output(s) as defined by W1 - W16 |
| ****Note: | If the output is on, it will pulse off for the defined time interval. If the output was off prior to the command, it will go on after the defined time interval. The pulse period may be set by a prior F17 A0 command. If it has not been set, the default pulse period will be used. |
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| F23 A1 | Pulse off selected channel 16 - 31 output(s) as defined by W1 - W16 |
| F9 A0 CLI | Clear channel 0 - 31 outputs, clear the FIFO, clear and reset the microprocessor, X = Q = 1 |
| F10 A0 CLM | Clear channel 0 - 15 outputs, Q = 1 if FIFO has room to store the command |
| F10 A1 CLM | Clear channed 16 - 31 outputs |
| F27 A0 TST | Test status, Q = 1 if both the FIFO is not full and both J1 and J2 C9 voltages are above +12 VDC. If Q = 0, the status of the individual conditions may be determined using any of the read commands above |
| +6 Volts | 500 mA |
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.70 Kg (1 lb. 8 oz.)
Model 5568 Isolated Digital Output Module
Mating connectors AMP 204744-1 w/hood 205-083-3
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