CAEN SY527 Instructions



The crate can be turned on locally simply by turning the key seen in the picture to the left. The systems can also be turned on remotely by simultaneously having the key turned to the right and by supplying a 12V, 40mA current to the input. If current is supplied to the remote input the crate will also generate a 12V, 40mA current to the output. This makes it so that several crates can be daisy chained together and all remotely turned on at once. The input and outputs both take male LEMO cables.


Next we have the system checks. The SY527 crates have several built in safety features that can be seen on the front panel:

The SY527 safety features include Over Temperature, which is tripped when the crate reaches a temperature greater than 60 degrees Celsius. Fan Failure, which occurs when the fans drop below 20% of their normal speed. And Power Failure, which occurs when there are problems in the low voltage supplies of the system. If any of these conditions are met their respective LED will glow red and the Check Passed output will be false. If these conditions are not met then the Check Passed LED will glow green and the Check Passed output will supply either a true TTL or true NIM signal.

The CAEN SY527 also includes many system control features on the front panel of the crate. The VSEL, ISEL, and Kill features include both outputs and inputs. This means that several crates can be daisy chained together in order to control these parameters simultaneously. However when daisy chaining crates, it is advisable to put a 50 ohm terminator into the outputs of the final crate to reduce signal noise. Here is a picture of the system control section of the crate.

Applying a true signal for at least thirty microseconds to this input or pressing the black button to the right of it will cause the whole system to restart. All channels will ramp to zero volts as quickly as possible during this reset.
The name VSEL is short for “Voltage Selection”. The CAEN system allows users to program two voltages into the system, these voltages are labeled V0 and V1. If the VSEL input is false, the CAEN system will set all HV channels to their programmed V0 voltage. If the VSEL input is true, the CAEN system will set all HV channels to their programmed V1 value. So this means False->V0, True->V1.

ISEL allows the user to select between two programmed current limits (I0 and I1). ISEL reading false corresponds to the system selecting I0, ISEL reading true corresponds to the system selecting I1.

A true signal lasting at least 10msec in the kill input will cause all channels to ramp to zero as quickly as possible.

Channel Status (output):
The Channel Status serves as an alarm system for the crate. Conditions for the alarm include Over Voltage, Over Current, and Under Voltage. Users are able to select whether or not these conditions will cause the alarm to be activated. The alarm itself can also be modified by users. Users are able to select a normal condition (high or low) and an alarm condition (level or pulsed). The Level alarm causes the signal to become a different voltage, a normal condition of “high” will correspond to a “low” alarm and a “low” normal will correspond to a “high alarm”. The pulse option will cause a pulsed rather than a constant signal.

This switch allows the user to select between the crate operating on NIM signals (-0.8V) or TTL signals (5.0V). All True and False conditions will correspond with this setting.

The interlock input is another safety feature of the CAEN systems. The interlock input allows all channels to be ramped down simultaneously, just like the kill input. The interlock input features two modes, “contact open” and “contact closed”. In the “contact open” setting the crate will shut down all channels if the ground connection to the input is removed, essentially operating like the kill input. In the “contact closed” setting, all channels will ramp down to 0V if the input is connected to ground. Unlike “kill” the interlocks have no output, so the interlocks of several crates cannot be chained together.

This switch allows users to enable and disable all of the HV channels on the crate. If the switch is in the middle position, all channels are disabled. If the switch is in the top position, all channels will be enabled. If the switch is in the bottom position, the crate will operate in “remote enable” mode. In this mode the channels will only be enabled if there is a true signal in the remote enable input. Remote enable features and output, meaning that the remote enables on many crates may be daisy chained together.

This port allows users to connect the CAEN crate to a computer using a male db-25 to female db-9 cable. The db-25 is the serial port on the crate, the db-9 is the serial port on the computer. Here is a diagram showing what each of the pins on the RS-232C port are:

In order to connect the crate to a computer, certain pins on the db-25 must connect to certain pins on the db-9. Here is a table showing what these connections must be.
db-25 db-9
7 5
6 6
3 2
2 3

Pin 7 on the db-25 must go to pin 5 on the db-9. Pin 6 on the db-25 must go to pin 6 on the db-9. Pin 3 on the db-25 must go to pin 2 on the db-9. Pin 2 on the db-25 must go to pin 3 on the db-9.

After powering on the CAEN SY527, the CAEN logo will appear on the screen. Press any key to move on to the main menu. Here is what the main menu should look like:

There are four submenus that can been accessed from the main menu. “Display Channel”, “Modify Channel”, “Crate Map”, and “I/O Config”.

Display Channel:
This menu allows user to enter the address of a specific channel in order to look at the properties of that channel.

In this picture, the user entered in the channel address 1.05 into the prompt, instructing the crate to display the properties of that channel. The address of a channel is determined which slot its card is plugged into and which spot the channel takes up on that card. So the address 1.05 means that the channel is on card 1 and takes up position 5 on that card. Once a channel has been selected, the user can look at other channels by pressing the “Next” and “Previous” buttons. If the user wants to make changes to the channel be displayed, they can press “Modify” which will take them to the “modify channel” menu. Hitting the “Return” button will take the user back to the main menu.

Modify Channel:
This menu allows the user to change the properties of the HV channels on the crate. Upon entering the modify channel screen, the user will see a page like this:

This allows the user to set V0, I0, and switch the channel on and off. Simply highlight a value and then hit change to set a new value. Pushing the “display” button will bring the user to the display menu. Hitting the “More” button allows the user to switch to a different page of values.

The picture above is of the second page of the “modify channel” menu. This page will appear when the user pushes the “more” button. There are 4 “modify channel” pages.

This page allows users to select maximum voltages and the ramp up and ramp down rates. The ramp up rate is the rate at which voltage will increase when it is instructed to increase. The ramp up rate is measured in Volts/Second. The ramp down rate is the rate at which voltage will decrease when it is instructed to decrease. Once again the rate is measured in volts/seconds.

This page allows the user to select trip times as well as power on the channel and power off the channel. The trip time is the amount of time until the system shuts down when the system is overcurrent. Trip time is set by tenths of seconds. For example setting the trip time to 20 would cause the trip time to be 2 seconds. Setting the trip time to 1000 will cause the trip time to be infinite.

Pushing the “crate map” button on the main menu will take the user to the crate map. The crate tells the user what kinds of cards are in each of the crates slots.

The crate map tells the user several properties of the cards plugged into the crate. It gives the card’s name, the number of channels on the card, the type of channel (positive, negative, or floating), the maximum output voltage, and the maximum output current, and the number of the slot in which the card is placed. If the slot is empty, the user will see “Not Present” on the left hand side. In the example pictured above, the crate map shows a card named “Mod. A516”. The card has 8 Channels which are floating. The card has a maximum output voltage of 12V, a maximum output current of 1.50A and is sitting in the 0 slot.

I/O Config:
The “I/O config” menu allows users to access 3 submenus. The RS-232 config, CAENET config, and Alarm Status.

RS232 Config:
This menu allows the user to change settings involving the RS232 port on the front of the crate.

Users are able to select the Baud rate of the connection, the parity, the number of bits per character, and the number of stop bits. Typically you are going to want to use the settings shown in the picture shown above, with baud rate=9600, no parity, 8bits/character, and 1 stop bit.

CAENET Config:
This menu allows users to edit the CAENET address of the crate.

Entering a new number into this menu and pressing enter will change the CAENET address of the crate.

This menu allows users to change the settings of the alarm system on the CAEN crate.

Normal level is the level of the signal from channel status output when there is no alarm. Alarm Type allows users to select what kind of alarm they would like to use. The level alarm changes the signal from the channel status output to the non-normal level. If low is selected for normal level, the alarm will be a high signal, and if the normal level is high the alarm will be a low level signal. Users may also use a pulsed signal which changes the signal from something constant into something pulsing when the alarm is activated. The alarm status menu also allows users to select which parameters set off the alarm. Users can select over current, over voltage, and under voltage as possible parameters for activating the alarm.


Making the Connection:
The first step to controlling the CAEN SY527 through a computer is establishing a connection. The way to make this connection can be seen in section 1 under the heading “RS232 Port”. Aside from the proper cabling, users should find and install the program Hyper Terminal. This program reads information from the computer’s db-9 port. Once the Hyper Terminal program is installed and opened, the user should select the following settings: Com-1, 9600 Baud, 8 bits/character, 1 stop bit, no hardware flow control. After these settings are selected and the CAEN is connected by cable to the computer, flip on the CAEN crate. The CAEN should be fully powered up after about a minute and the main menu should appear on the computer’s monitor.

Main Menu:

The main menu shown above is where the program automatically goes when a connection is established. Users can access 6 menus, Display, Protections, Crate, Map, Kill, and Alarms.

The display menu essentially works like the modify channel menu we saw with the manual control.

This is the first page of the display menu. This page allows the user to set V0 and I0 remotely as well as turn the power of the channel on and off. This menu also allows the user to see HVmax, which is the maximum voltage of a channel set by a potentiometer on the card in which the channel sits. This page also allows the user to monitor the current and voltage of each channel under the headings Vmon and Imon. This page also has a column labeled "Status" which tells the user if the channel is under voltage, over voltage, or over current.

This is the second page of the display menu. on this page the user can select several parameters for each channel. Most parameters on here are pretty standard, like SVmax for maximum voltage, and Rup for ramp up rate. However there are a few features found that are not found during manual operation. first there is PrOn, which gives certain channels priority of others when the crate is powering on, i.e. channels with greater priority are turned on first. PrOff works the same way and applies to powering off the crate. This menu also allows the user to enable or disable password protection on each on channel.


Pressing M at the main menu brings the user to the crate map which gives information about the cards in each slot of the crate, including model number, maximum voltage, maximum current, number of channels and the sign of the voltage produced.


Pressing C at the main menu allows the user to select a new crate to control remotely. All the user has to do to select a new crate is to type in the crate's CAENET address and press enter